Multicoordinated metal complexes for use in metathesis reactions

ABSTRACT

Improved catalysts useful in alkyne or olefin metathesis are made by bringing into contact a multi-coordinated metal complex comprising a multidentate Schiff base ligand, and one or more other ligands, with a selected activating compound under conditions such that at least partial cleavage of a bond between the metal and the multidentate Schiff base ligand of said metal complex occurs.

This application claims priority from U.S. provisional application No.60/710,073, filed Aug. 22, 2005 and from British patent applicationserial number GB 0517137.6 filed Aug. 22, 2005; the disclosures of eachare hereby incorporated by reference.

The present invention relates to multicoordinated metal complexes whichare useful as catalyst components, either alone or in combination withco-catalysts or initiators, in a wide variety of organic synthesisreactions including the metathesis of unsaturated compounds such asolefins and alkynes.

The present invention also relates to methods for making saidmulticoordinated metal complexes and to novel intermediates involved insuch methods. More particularly, the present invention relates tomulticoordinated complexes of metals such as but not limited toruthenium wherein said complexes comprise a modified Schiff base ligand,as well as methods for making the same and the use of suchmulticoordinated metal complexes as catalysts for the metathesis ofnumerous unsaturated hydrocarbons such as non-cyclic mono-olefins,dienes and alkynes, in particular for the ring-opening metathesispolymerisation of cyclic olefins.

BACKGROUND OF THE INVENTION

Olefin metathesis is a catalytic process including, as a key step, areaction between a first olefin and a first transition metal alkylidenecomplex, thus producing an unstable intermediate metallacyclobutane ringwhich then undergoes transformation into a second olefin and a secondtransition metal alkylidene complex according to equation (1) hereunder.Reactions of this kind are reversible and in competition with oneanother, so the overall result heavily depends on their respective ratesand, when formation of volatile or insoluble products occur,displacement of equilibrium.

Several exemplary but non-limiting types of metathesis reactions formono-olefins or di-olefins are shown in equations (2) to (5)herein-after. Removal of a product, such as ethylene in equation (2),from the system can dramatically alter the course and/or rate of adesired metathesis reaction, since ethylene reacts with an alkylidenecomplex in order to form a methylene (M=CH₂) complex, which is the mostreactive and also the least stable of the alkylidene complexes.

Of potentially greater interest than homo-coupling (equation 2) iscross-coupling between two different terminal olefins. Couplingreactions involving dienes lead to linear and cyclic dimers, oligomers,and, ultimately, linear or cyclic polymers (equation 3). In general, thelatter reaction called acyclic diene metathesis (hereinafter referred toas ADMET) is favoured in highly concentrated solutions or in bulk, whilecyclisation is favoured at low concentrations. When intra-molecularcoupling of a diene occurs so as to produce a cyclic alkene, the processis called ring-closing metathesis (hereinafter referred to as RCM)(equation 4). Strained cyclic olefins can be opened and oligomerised orpolymerised (ring opening metathesis polymerisation (hereinafterreferred to as ROMP) shown in equation 5). When the alkylidene catalystreacts more rapidly with the cyclic olefin (e.g. a norbornene or acyclobutene) than with a carbon-carbon double bond in the growingpolymer chain, then a “living ring opening metathesis polymerisation”may result, i.e. there is little termination during or after thepolymerization reaction.

A large number of catalyst systems comprising well-defined singlecomponent metal carbene complexes have been prepared and utilized inolefin metathesis. One major development in olefin metathesis was thediscovery of the ruthenium and osmium carbene complexes by Grubbs andco-workers. U.S. Pat. No. 5,977,393 discloses Schiff base derivatives ofsuch compounds, which are useful as olefin metathesis catalysts, whereinthe metal is coordinated by a neutral electron donor, such as atriarylphosphine or a tri(cyclo)alkylphosphine, and by an anionicligand. Such catalysts show an improved thermal stability whilemaintaining metathesis activity even in polar protic solvents. They arealso able to promote cyclisation of, for instance, diallylaminehydrochloride into dihydropyrrole hydrochloride. Remaining problems tobe solved with the carbene complexes of Grubbs are (i) improving bothcatalyst stability (i.e. slowing down decomposition) and metathesisactivity at the same time and (ii) broadening the range of organicproducts achievable by using such catalysts, e.g. providing ability toring-close highly substituted dienes into tri- and tetra-substitutedolefins.

International patent application published as WO 99/00396 discloses atleast penta-coordinated ruthenium and osmium complexes including twoanionic ligands and two monodentate neutral electron donor ligands andfurther wherein one of the coordinating ligands is aheteroatom-containing alkylidene of the formula=CH—Z—R, wherein Z issulfur, hydrocarbylphosphino, oxygen or hydrocarbylamino, and wherein Ris hydrocarbyl.

International patent application published as WO 03/062253 disclosesfive-coordinate metal complexes, salt, solvates or enantiomers thereof,comprising a carbene ligand, a multidentate ligand and one or more otherligands, wherein at least one of said other ligands is a constraintsteric hindrance ligand having a pKa of at least 15. More specifically,the said document discloses five-coordinate metal complexes having oneof the general formulae (IA) and (IB) referred to in FIG. 1, wherein:

-   -   M is a metal selected from the group consisting of groups 4, 5,        6, 7, 8, 9, 10, 11 and 12 of the Periodic Table, preferably a        metal selected from ruthenium, osmium, iron, molybdenum,        tungsten, titanium, rhenium, copper, chromium, manganese,        rhodium, vanadium, zinc, gold, silver, nickel and cobalt;    -   Z is selected from the group consisting of oxygen, sulphur,        selenium, NR″″, PR″″, AsR″″ and SbR″″;    -   R″, R′″ and R″″ are each a radical independently selected from        the group consisting of hydrogen, C₁₋₆ alkyl, C₃₋₈ cycloalkyl,        C₁₋₆ alkyl-C₁₋₆ alkoxysilyl, C₁₋₆ alkyl-aryloxysilyl, C₁₋₆        alkyl-C₃₋₁₀ cycloalkoxysilyl, aryl and heteroaryl, or R″ and R′″        together form an aryl or heteroaryl radical, each said radical        (when different from hydrogen) being optionally substituted with        one or more, preferably 1 to 3, substituents R₅ each        independently selected from the group consisting of halogen        atoms, C₁₋₆ alkyl, C₁₋₆ alkoxy, aryl, alkylsulfonate,        arylsulfonate, alkylphosphonate, arylphosphonate, C₁₋₆        alkyl-C₁₋₆ alkoxysilyl, C₁₋₆ alkyl-aryloxysilyl, C₁₋₆        alkyl-C₃₋₁₀ cycloalkoxysilyl, alkylammonium and arylammonium;    -   R′ is either as defined for R″, R′″ and R″″ when included in a        compound having the general formula (IA) or, when included in a        compound having the general formula (IB), is selected from the        group consisting of C₁₋₆ alkylene and C₃₋₈ cycloalkylene, the        said alkylene or cycloalkylene group being optionally        substituted with one or more substituents R₅;    -   R₁ is a constraint steric hindrance group having a pKa of at        least about 15;    -   R₂ is an anionic ligand;    -   R₃ and R₄ are each hydrogen or a radical selected from the group        consisting of C₁₋₂₀ alkyl, C₂₋₂₀ alkenyl, C₂₋₂₀ alkynyl, C₁₋₂₀        carboxylate, C₁₋₂₀ alkoxy, C₂₋₂₀ alkenyloxy, C₂₋₂₀ alkynyloxy,        aryl, aryloxy, C₁₋₂₀ alkoxycarbonyl, C₁₋₈ alkylthio, C₁₋₂₀        alkylsulfonyl, C₁₋₂₀ alkylsulfinyl C₁₋₂₀ alkylsulfonate,        arylsulfonate, C₁₋₂₀ alkylphosphonate, arylphosphonate, C₁₋₂₀        alkylammonium and arylammonium;    -   R′ and one of R₃ and R₄ may be bonded to each other to form a        bidentate ligand;    -   R″ and R″″ may be bonded to each other to form an aliphatic ring        system including a heteroatom selected from the group consisting        of nitrogen, phosphorous, arsenic and antimony;    -   R₃ and R₄ together may form a fused aromatic ring system, and    -   y represents the number of sp₂ carbon atoms between M and the        carbon atom bearing R₃ and R₄ and is an integer from 0 to 3        inclusive, salts, solvates and enantiomers thereof.        These five-coordinate metal complexes of WO 03/062253 proved to        be very efficient olefin metathesis catalysts. International        patent application published as WO 2005/035121 discloses at        least tetra-coordinated metal complexes, salts, solvates and        enantiomers thereof, comprising:    -   a multidentate ligand being coordinated with the metal by means        of a nitrogen atom and at least one heteroatom selected from the        group consisting of oxygen, sulphur, selenium, nitrogen,        phosphorus, arsenic and antimony, wherein each of nitrogen,        phosphorus, arsenic and antimony is substituted with a radical        R″″ selected from the group consisting of hydrogen, C₁₋₇ alkyl,        C₃₋₁₀ cycloalkyl, aryl and heteroaryl;    -   a non-anionic unsaturated ligand L¹ selected from the group        consisting of aromatic and unsaturated cycloaliphatic groups,        preferably aryl, heteroaryl and C₄₋₂₀ cycloalkenyl groups, the        said aromatic or unsaturated cycloaliphatic group being        optionally substituted with one or more C₁₋₇ alkyl groups or        electron-withdrawing groups such as, but not limited to,        halogen, nitro, cyano, (thio)carboxylic acid, (thio)carboxylic        acid (thio)ester, (thio)carboxylic acid (thio)amide,        (thio)carboxylic acid anhydride and (thio) carboxylic acid        halide; and    -   a non-anionic ligand L² selected from the group consisting of        C₁₋₇ alkyl, C₃₋₁₀ cycloalkyl, aryl, arylalkyl, alkylaryl and        heterocyclic, the said group being optionally substituted with        one or more preferably electron-withdrawing substituents such        as, but not limited to, halogen, nitro, cyano, (thio)carboxylic        acid, (thio)carboxylic acid (thio)ester, (thio)carboxylic acid        (thio)amide, (thio)carboxylic acid anhydride and (thio)        carboxylic acid halide.        The multidentate ligand of such an at least tetra-coordinated        metal complex may be a bidentate or tridentate Schiff base. WO        2005/035121 also discloses hexa-coordinated metal complexes,        salts, solvates and enantiomers thereof, comprising:    -   a multidentate ligand being coordinated with the metal by means        of a nitrogen atom and at least one heteroatom selected from the        group consisting of oxygen, sulphur, selenium, nitrogen,        phosphorus, arsenic and antimony, wherein each of nitrogen,        phosphorus, arsenic and antimony is substituted with a radical        R″″ selected from the group consisting of hydrogen, C₁₋₇ alkyl,        C₃₋₁₀ cycloalkyl, aryl and heteroaryl;    -   at least one non-anionic bidentate ligand L³ being different        from the multidentate ligand; and    -   at most two anionic ligands L⁴, wherein one or more of said        anionic ligands L⁴ may be each replaced with a solvent S, in        which case the said hexa-coordinated metal complex is a cationic        species associated with an anion A.        The multidentate ligand of such an at least hexa-coordinated        metal complex may be a bidentate or tridentate Schiff base.        These tetra-coordinated and hexa-coordinated metal complexes of        WO 2005/035121 proved to be very efficient olefin metathesis        catalysts, especially in the ring opening metathesis        polymerisation of norbornene and derivatives thereof.

However there is a continuous need in the art for improving catalystefficiency, i;e. improving the yield of the reaction catalysed by thesaid catalyst component after a certain period of time under givenconditions (e.g. temperature, pressure, solvent and reactant/catalystratio) or else, at a given reaction yield, providing milder conditions(lower temperature, pressure closer to atmospheric pressure, easierseparation and purification of product from the reaction mixture) orrequiring a smaller amount of catalyst (i.e. a higher reactant/catalystratio) and thus resulting in more economic and environment-friendlyoperating conditions. This need is still more stringent for use inreaction-injection molding (RIM) processes such as, but not limited to,the bulk polymerisation of endo- or exo-dicyclopentadiene, orformulations thereof.

WO 93/20111 describes osmium- and ruthenium-carbene compounds withphosphine ligands as purely thermal catalysts for ring-openingmetathesis polymerization of strained cycloolefins, in which cyclodienessuch as dicyclopentadiene act as catalyst inhibitors and cannot bepolymerized. This is confirmed for instance by example 3 of U.S. Pat.No. 6,284,852, wherein dicyclopentadiene did not yield any polymer, evenafter days in the presence of certain ruthenium carbene complexes havingphosphine ligands. However, U.S. Pat. No. 6,235,856 teaches thatdicyclopentadiene is accessible to thermal metathesis polymerizationwith a single-component catalyst if carbene-free ruthenium(II)- orosmium(II)-phosphine catalysts are used.

U.S. Pat. No. 6,284,852 discloses enhancing the catalytic activity of aruthenium carbene complex of the formula A_(x)L_(y)X_(z)Ru═CHR′, whereinx=0, 1 or 2, y=0, 1 or 2, and z=1 or 2 and wherein R′ is hydrogen or asubstituted or unsubstituted alkyl or aryl, L is any neutral electrondonor, X is any anionic ligand, and A is a ligand having a covalentstructure connecting a neutral electron donor and an anionic ligand, bythe deliberate addition of specific amounts of acid not present as asubstrate or solvent, the said enhancement being for a variety of olefinmetathesis reactions including ROMP, RCM, ADMET and cross-metathesis anddimerization reactions. According to U.S. Pat. No. 6,284,852, organic orinorganic acids may be added to the catalysts either before or duringthe reaction with an olefin, with longer catalyst life being observedwhen the catalyst is introduced to an acidic solution of olefin monomer.The amounts of acid disclosed in examples 3 to 7 of U.S. Pat. No.6,284,852 range from 0.3 to 1 equivalent of acid, with respect to thealkylidene moiety. In particular, the catalyst systems of example 3 (inparticular catalysts being Schiff-base-substituted complexes includingan alkylidene ligand and a phosphine ligand) in the presence of HCl asan acid achieve ROMP of dicyclopentadiene within less than 1 minute atroom temperature in the absence of a solvent, and ROMP of anoxanorbornene monomer within 15 minutes at room temperature in thepresence of a protic solvent (methanol), however at monomer/catalystratios which are not specified.

U.S. Pat. No. 6,284,852 also shows alkylidene ruthenium complexes which,after activation in water with a strong acid, quickly and quantitativelyinitiate living polymerization of water-soluble polymers, resulting in asignificant improvement over existing ROMP catalysts. It further allegesthat the propagating species in these reactions is stable (a propagatingalkylidene species was observed by proton nuclear magnetic resonance)and that the effect of the acid in the system appears to be twofold: inaddition to eliminating hydroxide ions which would cause catalystdecomposition, catalyst activity is also enhanced by protonation ofphosphine ligands. It is also taught that, remarkably, the acids do notreact with the ruthenium alkylidene bond.

Although providing an improvement over existing ROMP catalysts, theteaching of U.S. Pat. No. 6,284,852 is however limited in many aspects,namely:

-   -   because its alleged mechanism of acid activation involves the        protonation of phosphine ligands, it is limited to alkylidene        ruthenium complexes including at least one phosphine ligand;    -   it does not disclose reacting a Schiff-base-substituted        ruthenium complex with an acid under conditions such that said        acid at least partly cleaves a bond between ruthenium and the        Schiff base ligand of said complex.

U.S. Pat. No. 6,284,852 does not either teach the behaviour, in thepresence of an acid, of ruthenium complexes wherein ruthenium iscoordinated with a vinylidene ligand, an allenylidene ligand or aN-heterocyclic carbene ligand.

U.S. Pat. No. 6,284,852 therefore has left open ways for the study ofmulti-coordinated metal complexes, in particular multicoordinatedruthenium and osmium complexes in an acidic, preferably a stronglyacidic, environment when used for olefin or alkyne metathesis reactionsincluding ROMP, RCM, ADMET, and for cross-metathesis and dimerizationreactions.

Therefore one goal of this invention is the design of new and usefulcatalytic species, especially based on multicoordinated transition metalcomplexes, having unexpected properties and improved efficiency inolefin or alkyne metathesis reactions.

Another goal of this invention is to efficiently perform olefin oralkyne metathesis reactions, in particular ring opening polymerizationof strained cyclic olefins (including cationic forms of such monomerssuch as, but not limited to, strained cyclic olefins includingquaternary ammonium salts), in the presence of multicoordinatedtransition metal complexes without being limited by the requirement of aphosphine ligand in said complexes.

There is also a specific need in the art, which is yet another goal ofthis invention, for improving reaction-injection molding (RIM)processes, resin transfer molding (RTM) processes, pultrusion, filamentwinding and reactive rotational molding (RRM) processes such as, but notlimited to, the bulk polymerisation of endo- or exo-dicyclopentadiene,or copolymerization thereof with other monomers, or formulationsthereof. More specifically there is a need to improve such processeswhich are performed in the presence of multicoordinated transition metalcomplexes, in particular ruthenium complexes, having variouscombinations of ligands but which do not necessarily comprise phosphineligands. All the above needs constitute the various goals to be achievedby the present invention, nevertheless other advantages of thisinvention will readily appear from the following description.

SUMMARY OF THE INVENTION

In a first aspect the present invention is based on the unexpectedfinding that improved catalysts useful in a number of organic synthesisreactions such as, but not limited to, the metathesis of unsaturatedcompounds such as olefins and alkynes can be obtained by bringing intocontact a multi-coordinated metal complex, preferably an at leasttetra-coordinated transition metal complex comprising a multidentateSchiff base ligand and one or more other ligands (such as, but notlimited to, the metal complexes of WO 03/062253 or WO 2005/035121), withan activating metal or silicon compound selected from the groupconsisting of:

-   -   copper (I) halides,    -   zinc compounds represented by the formula Z_(n)(R₅)₂, wherein R₅        is halogen, C₁₋₇ alkyl or aryl,    -   tin compounds represented by the formula SnR₉R₁₀R₁₁R₁₂ wherein        each of R₉, R₁₀, R₁₁ and R₁₂ is independently selected from the        group consisting of halogen, C₁₋₂₀ alkyl, C₃₋₁₀ cycloalkyl,        aryl, benzyl and C₂₋₇ alkenyl, and    -   silicon compounds represented by the formula SiR₁₃R₁₄R₁₅R₁₆        wherein each of R₁₃, R₁₄, R₁₅ and R₁₆ is independently selected        from the group consisting of hydrogen, halogen, C₁₋₂₀ alkyl,        halo C₁₋₇ alkyl, aryl, heteroaryl and vinyl, under conditions        such that at least partial cleavage of a bond between the metal        and the multidentate Schiff base ligand of said        multi-coordinated metal complex occurs.

In a second aspect the present invention is based on the unexpectedfinding that improved catalysts useful in a number of organic synthesisreactions such as, but not limited to, metathesis reactions ofunsaturated organic compounds such as olefins and alkynes can beobtained by bringing into contact a multi-coordinated metal complex,preferably an at least tetra-coordinated transition metal complexcomprising a multidentate Schiff base ligand and one or more otherligands (such as, but not limited to, the metal complexes of WO03/062253 or WO 2005/035121), with an activating compound comprising atleast one halogen atom directly bonded to at least one atom having anatomic mass from 27 to 124 and being selected from the group consistingof groups IB, IIB, IIIA, IVB, IVA and VA of the Periodic Table ofelements under conditions such that at least partial cleavage of a bondbetween the metal and the multidentate Schiff base ligand of saidmulti-coordinated metal complex occurs. The activating compound mayfurther comprise, depending upon the nature of the atom having an atomicmass from 27 to 124, one or more hydrogen atoms and/or one or moresaturated or unsaturated hydrocarbyl groups directly bonded to said atleast one atom having an atomic mass from 27 to 124. The atom having anatomic mass from 27 to 124 may be a metal or a non-metal, according tothe classification of elements standard in the art.

In one specific embodiment, the present invention is based on theunexpected finding that new and useful catalytic species can be suitablyobtained by reacting an activating compound such as defined herein-abovewith a multi-coordinated metal complex, preferably an at leasttetra-coordinated transition metal complex comprising a multidentateSchiff base ligand and further comprising a set of one or more otherligands such as, but not limited to, anionic ligands, N-heterocycliccarbene ligands, alkylidene ligands, vinylidene ligands, indenylideneligands and allenylidene ligands, wherein said set of other ligands isfree from any phosphine ligand. More specifically, this invention isbased on the finding that suitable conditions for the activationreaction between the activating compound and the multi-coordinated metalcomplex are conditions which permit, in one or several steps, the atleast partial decoordination of the multidentate Schiff base ligandthrough cleavage of the imine bond to the metal center and optionallythe coordination of the nitrogen atom of said Schiff base to the metalor silicon of the activating compound.

Based on these findings, the present invention thus provides newcatalytic species or products, or mixtures of species, deriving from thereaction (hereinafter also referred as “activation”) between thestarting multi-coordinated Schiff-base-substituted metal complex andsaid activating compound. In the broader acceptance, these species maybe monometallic species represented by the general formula:

[M(L_(c))(L₂)(X)(SB_(m))]

wherein

-   -   M is a metal selected from the group consisting of groups 4, 5,        6, 7, 8, 9, 10, 11 and 12 of the Periodic Table, preferably a        metal selected from ruthenium, osmium, iron, molybdenum,        tungsten, titanium, rhenium, copper, chromium, manganese,        rhodium, vanadium, zinc, gold, silver, nickel and cobalt;    -   SB_(m) is a modified Schiff base ligand, wherein modification        comprises coordination of the nitrogen atom of said Schiff base        to the metal or silicon atom of the activating compound;    -   L_(c) is a carbene ligand, preferably selected from the group        consisting of alkylidene ligands, vinylidene ligands,        indenylidene ligands and allenylidene ligands;    -   L₂ is a non-anionic ligand, preferably other than a phosphine        ligand; and    -   X is an anionic ligand,        including salts, solvates and enantiomers thereof.

These species may also be bimetallic species represented by the generalformula:

[M(L_(c))(SB_(m))(X₁)(X₂)(M′)(X₃)(L)]X⁻

wherein

-   -   M and M′ are each a metal independently selected from the group        consisting of groups 4, 5, 6, 7, 8, 9, 10, 11 and 12 of the        Periodic Table, preferably a metal selected from ruthenium,        osmium, iron, molybdenum, tungsten, titanium, rhenium, copper,        chromium, manganese, rhodium, vanadium, zinc, gold, silver,        nickel and cobalt;    -   SB_(m) is a modified Schiff base ligand, wherein modification        comprises coordination of the nitrogen atom of said Schiff base        to the metal or silicon atom of the activating compound;    -   L_(c) is a carbene ligand, preferably selected from the group        consisting of alkylidene ligands, vinylidene ligands,        indenylidene ligands, heteroatom-containing alkylidene ligands        and allenylidene ligands;    -   L is a non-anionic ligand, preferably other than a phosphine        ligand; and    -   X₁, X₂ and X₃ are each independently selected from anionic        ligands,        including salts, solvates and enantiomers thereof.

When starting from a multi-coordinated Schiff-base-substitutedmonometallic complex, such new species or products may for instance takethe form of one or more monometallic species being represented by thegeneral formula (VI): or by the general formula (VII):

wherein

-   -   M is a metal selected from the group consisting of groups 4, 5,        6, 7, 8, 9, 10, 11 and 12 of the Periodic Table, preferably a        metal selected from ruthenium, osmium, iron, molybdenum,        tungsten, titanium, rhenium, copper, chromium, manganese,        rhodium, vanadium, zinc, gold, silver, nickel and cobalt;    -   W is selected from the group consisting of oxygen, sulphur,        selenium, NR″″, PR″″, AsR″″ and SbR″″;    -   R″, R′″ and R″″ are each a substituent independently selected        from the group consisting of hydrogen, C₁₋₆ alkyl, C₃₋₈        cycloalkyl, C₁₋₆ alkyl-C₁₋₆ alkoxysilyl, C₁₋₆        alkyl-aryloxysilyl, C₁₋₆ alkyl-C₃₋₁₀ cycloalkoxysilyl, aryl and        heteroaryl, or R″ and R′″ together form an aryl or heteroaryl        substituent, each said substituent (when different from        hydrogen) being itself optionally substituted with one or more,        preferably 1 to 3, substituents R₂₀ each independently selected        from the group consisting of halogen atoms, C₁₋₆ alkyl, C₁₋₆        alkoxy, aryl, alkylsulfonate, arylsulfonate, alkylphosphonate,        arylphosphonate, C₁₋₆ alkyl-C₁₋₆ alkoxysilyl, C₁₋₆        alkylaryloxysilyl, C₁₋₆ alkyl-C₃₋₁₀ cycloalkoxysilyl,        alkylammonium and arylammonium;    -   R′ is either as defined for R″, R′″ and R″″ when included in a        compound having the general formula (VI) or, when included in a        compound having the general formula (VII), is selected from the        group consisting of C₁₋₆ alkylene and C₃₋₈ cycloalkylene, the        said alkylene or cycloalkylene group being optionally        substituted with one or more substituents R₂₀ as defined herein        before;    -   L₂ is a non-anionic ligand, preferably other than a phosphine        ligand;    -   X is an anionic ligand;    -   R₃ and R₄ are each hydrogen or a radical selected from the group        consisting of C₁₋₂₀ alkyl, C₂₋₂₀ alkenyl, C₂₋₂₀ alkynyl, C₁₋₂₀        carboxylate, C₁₋₂₀ alkoxy, C₂₋₂₀ alkenyloxy, C₂₋₂₀ alkynyloxy,        aryl, aryloxy, C₁₋₂₀ alkoxycarbonyl, C₁₋₈ alkylthio, C₁₋₂₀        alkylsulfonyl, C₁₋₂₀ alkylsulfinyl C₁₋₂₀ alkylsulfonate,        arylsulfonate, C₁₋₂₀ alkylphosphonate, arylphosphonate, C₁₋₂₀        alkylammonium and arylammonium;    -   R′ and one of R₃ and R₄ may be bonded to each other to form a        bidentate ligand;    -   R″ and R″″ may be bonded to each other to form an aliphatic ring        system including a heteroatom selected from the group consisting        of nitrogen, phosphorous, arsenic and antimony;    -   R₃ and R₄ together may form a fused aromatic ring system,    -   y represents the number of sp₂ carbon atoms between M and the        carbon atom bearing R₃ and R₄ and is an integer from 0 to 3        inclusive, and    -   Z is an activating metal or silicon compound such as defined        herein-above,        including salts, solvates and enantiomers thereof.

When starting from a multi-coordinated Schiff-base-substitutedbimetallic complex, such new species or products may for instance takethe form of one or more bimetallic species being represented by thestructural formula (X):

or by the structural formula (XI):

wherein

-   -   M and M′ are each a metal independently selected from the group        consisting of groups 4, 5, 6, 7, 8, 9, 10, 11 and 12 of the        Periodic Table, preferably a metal selected from ruthenium,        osmium, iron, molybdenum, tungsten, titanium, rhenium, copper,        chromium, manganese, rhodium, vanadium, zinc, gold, silver,        nickel and cobalt;    -   W, R′, R″, R″′, R′″, y, R₃ and R₄ are as defined in        formulae (VI) and (VII) hereinabove;    -   X₁, X₂ and X₃ are each independently selected from anionic        ligands,    -   L is a non-anionic ligand, preferably other than a phosphine        ligand, and    -   Z is an activating metal or silicon compound such as defined        herein-above,        including salts, solvates and enantiomers thereof.

In another specific embodiment, the present invention is based on theunexpected finding that useful catalytic species can be suitablyobtained by reacting a metal or silicon activating compound such asdefined hereinabove with respect to the first aspect of the invention,provided that said metal or silicon activating compound includes atleast one halogen atom, or by reacting an activating compound such asdefined with respect to the second aspect of the invention, with saidmulti-coordinated metal complex (preferably an at leasttetra-coordinated transition metal complex comprising a multidentateSchiff base ligand such as specified herein-above) in the presence of atleast one further reactant being an organic acid or having the formulaRYH, wherein Y is selected from the group consisting of oxygen, sulfurand selenium, and R is selected from the group consisting of hydrogen,aryl, arylalkyl, heteocyclic, heterocyclic-substituted alkyl, C₂₋₇alkenyl and C₁₋₇ alkyl. According to this specific embodiment, a strongacid (such as a hydrogen halide) may be formed in situ by the reactionof said activating compound, e.g. metal or silicon activating compound,with said further reactant (e.g. a reactant having the formula RYH), andsaid strong acid if produced in sufficient amount may in turn be able:

-   -   in a first step, to protonate the multidentate Schiff base        ligand and decoordinate the nitrogen atom of the imino group of        said multidentate Schiff base ligand from the complexed metal,        and    -   in a second step, to decoordinate the further heteroatom of said        multidentate Schiff base ligand from the complexed metal.

In this specific embodiment, at least partial cleavage of a bond betweenthe metal and the multidentate Schiff base ligand of saidmulti-coordinated metal complex occurs like in the absence of thefurther reactant (e.g. one having the formula RYH), but coordination ofthe nitrogen atom of the Schiff base ligand to the metal or silicon orother atom having an atomic mass from 27 to 124 of the activatingcompound occurs less frequently because it competes unfavourably withthe protonation/decoordination mechanism resulting from the in situgeneration of a strong acid (such as a hydrogen halide). Thisalternative mechanism is however quite effective in the catalysis ofmetathesis reactions of organic compounds since it provides a morerandom distribution of the strong acid formed in the reaction mixturethan if the same strong acid is introduced directly in the presence ofthe multicoordinated metal complex.

The new catalytic species of the invention may be producedextra-temporaneously, separated, purified and conditioned for separateuse in organic synthesis reactions later on, or they may be produced insitu during the relevant chemical reaction (e.g. metathesis ofunsaturated organic compounds) by introducing a suitable amount of the(e.g. metal or silicon) activating compound into the reaction mixturebefore, simultaneously with, or alternatively after the introduction ofthe starting Schiff base metal complex. The present invention alsoprovides catalytic systems including, in addition to said new catalyticspecies or reaction products, a carrier suitable for supporting saidcatalytic species or reaction products.

The present invention also provides methods and processes involving theuse of such new catalytic species or reaction products, or any mixtureof such species, or such catalytic systems, in a wide range of organicsynthesis reactions including the metathesis of unsaturated compoundssuch as olefins and alkynes and certain reactions involving the transferof an atom or group to an ethylenically or acetylenically unsaturatedcompound or another reactive substrate, such as atom transfer radicalpolymerisation, atom transfer radical addition, vinylation,cyclopropanation of ethylenically unsaturated compounds, and the like.In particular, this invention provides an improved process for the ringopening polymerization of strained cyclic olefins such as, but notlimited to, dicyclopentadiene.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows bidentate Schiff base ligands having the general formulae(I A) and (I B) that may be included in multicoordinated metal complexessuitable for modification according to an embodiment of the presentinvention.

FIG. 2 shows tetradentate Schiff base ligands having the generalformulae (II A) and (II B) that may be included in multicoordinatedmetal complexes suitable for modification according to anotherembodiment of the present invention.

FIG. 3 shows tetradentate Schiff base ligands having the generalchemical formulae (III A) and (III B) that may be included inmulticoordinated metal complexes suitable for modification according tothis invention.

FIG. 4 shows tridentate Schiff base ligands having the general chemicalformulae (IV D) that may be included in multicoordinated metal complexessuitable for modification according to the present invention.

FIG. 5 shows a manufacturing scheme for a multicoordinated rutheniumcomplex suitable for modification according to the present invention.

FIG. 6 shows monometallic complexes having the general formula (VA),derived from a tetradentate Schiff base ligand (IIIA), and the generalformula (VB) suitable for modification according to the presentinvention

DEFINITIONS

As used herein, the term complex, or coordination compound, refers tothe result of a donor-acceptor mechanism or Lewis acid-base reactionbetween a metal (the acceptor) and several neutral molecules or ioniccompounds called ligands, each containing a non-metallic atom or ion(the donor). Ligands that have more than one atom with lone pairs ofelectrons (i.e. more than one point of attachment to the metal center)and therefore occupy more than one coordination site are calledmultidentate ligands. The latter, depending upon the number ofcoordination sites occupied, include bidentate, tridentate andtetradentate ligands.

As used herein, the term “monometallic” refers to a complex in whichthere is a single metal center. As used herein, the term“heterobimetallic” refers to a complex in which there are two differentmetal centers. As used herein, the term “homobimetallic” refers to acomplex having two identical metal centers, which however need not haveidentical ligands or coordination number.

As used herein with respect to a substituent, ligand or group, the term“C₁₋₇ alkyl” means straight and branched chain saturated acyclichydrocarbon monovalent radicals having from 1 to 7 carbon atoms such as,for example, methyl, ethyl, propyl, n-butyl, 1-methylethyl (isopropyl),2-methylpropyl (isobutyl), 1,1-dimethylethyl (ter-butyl),2-methyl-butyl, n-pentyl, dimethylpropyl, n-hexyl, 2-methylpentyl,3-methylpentyl, n-heptyl and the like; optionally the carbon chainlength of such group may be extended to 20 carbon atoms.

As used herein with respect to a linking group, the term “alkylene”means the divalent hydrocarbon radical corresponding to the abovedefined C₁₋₇ alkyl, such as methylene, bis(methylene), tris(methylene),tetramethylene, hexamethylene and the like.

As used herein with respect to a substituent, ligand or group, the term“C₃₋₁₀ cycloalkyl” means a mono- or polycyclic saturated hydrocarbonmonovalent radical having from 3 to 10 carbon atoms, such as forinstance cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl,cyclooctyl and the like, or a C₇₋₁₀ polycyclic saturated hydrocarbonmonovalent radical having from 7 to 10 carbon atoms such as, forinstance, norbornyl, fenchyl, trimethyltricycloheptyl or adamantyl.

As used herein with respect to a linking group, and unless otherwisestated, the term “C₃₋₁₀ cycloalkylene” means the divalent hydrocarbonradical corresponding to the above defined C₃₋₁₀ cycloalkyl, such as1,2-cyclohexylene and 1,4-cyclohexylene.

As used herein with respect to a substituent, ligand or group, andunless otherwise stated, the term “aryl” designates any mono- orpolycyclic aromatic monovalent hydrocarbon radical having from 6 up to30 carbon atoms such as but not limited to phenyl, naphthyl,anthracenyl, phenantracyl, fluoranthenyl, chrysenyl, pyrenyl,biphenylyl, terphenyl, picenyl, indenyl, biphenyl, indacenyl,benzocyclobutenyl, benzocyclooctenyl and the like, including fusedbenzo-C₄₋₈ cycloalkyl radicals (the latter being as defined above) suchas, for instance, indanyl, tetrahydronaphtyl, fluorenyl and the like,all of the said radicals being optionally substituted with one or moresubstituents selected from the group consisting of halogen, amino,nitro, hydroxyl, sulfhydryl and nitro, such as for instance4-fluorophenyl, 4-chlorophenyl, 3,4-dichlorophenyl,2,6-diisopropyl-4-bromophenyl, pentafluorophenyl and 4-cyanophenyl.

As used herein with respect to a linking group, and unless otherwisestated, the term “arylene” means the divalent hydrocarbon radicalcorresponding to the above defined aryl, such as phenylene, toluylene,xylylene, naphthylene and the like.

As used herein with respect to a combination of two substitutinghydrocarbon radicals, and unless otherwise stated, the term “homocyclic”means a mono- or polycyclic, saturated or mono-unsaturated orpolyunsaturated hydrocarbon radical having from 4 up to 15 carbon atomsbut including no heteroatom in the said ring; for instance the saidcombination forms a C₂₋₆ alkylene radical, such as tetramethylene, whichcyclizes with the carbon atoms to which the said two substitutinghydrocarbon radicals are attached.

As used herein with respect to a substituent (or a combination of twosubstituents), ligand or group, and unless otherwise stated, the term“heterocyclic” means a mono- or polycyclic, saturated ormono-unsaturated or polyunsaturated monovalent hydrocarbon radicalhaving from 2 up to 15 carbon atoms and including one or moreheteroatoms in one or more heterocyclic rings, each of said rings havingfrom 3 to 10 atoms (and optionally further including one or moreheteroatoms attached to one or more carbon atoms of said ring, forinstance in the form of a carbonyl or thiocarbonyl or selenocarbonylgroup, and/or to one or more heteroatoms of said ring, for instance inthe form of a sulfone, sulfoxide, N-oxide, phosphate, phosphonate orselenium oxide group), each of said heteroatoms being independentlyselected from the group consisting of nitrogen, oxygen, sulfur, seleniumand phosphorus, also including radicals wherein a heterocyclic ring isfused to one or more aromatic hydrocarbon rings for instance in the formof benzo-fused, dibenzo-fused and naphto-fused heterocyclic radicals;within this definition are included heterocyclic radicals such as, butnot limited to, diazepinyl, oxadiazinyl, thiadiazinyl, dithiazinyl,triazolonyl, diazepinonyl, triazepinyl, triazepinonyl, tetrazepinonyl,benzoquinolinyl, benzothiazinyl, benzothiazinonyl, benzoxathiinyl,benzodioxinyl, benzodithiinyl, benzoxazepinyl, benzo-thiazepinyl,benzodiazepinyl, benzodioxepinyl, benzodithiepinyl, benzoxazocinyl,benzothiazocinyl, benzodiazocinyl, benzoxathiocinyl, benzodioxocinyl,benzotrioxepinyl, benzoxathiazepinyl, benzoxadiazepinyl,benzothia-diazepinyl, benzotriazepinyl, benzoxathiepinyl,benzotriazinonyl, benzoxazolinonyl, azetidinonyl, azaspiroundecyl,dithiaspirodecyl, selenazinyl, selenazolyl, selenophenyl, hypoxanthinyl,azahypoxanthinyl, bipyrazinyl, bipyridinyl, oxazolidinyl,diselenopyrimidinyl, benzodioxocinyl, benzopyrenyl, benzopyranonyl,benzophenazinyl, benzoquinolizinyl, dibenzocarbazolyl, dibenzoacridinyl,dibenzophenazinyl, dibenzothiepinyl, dibenzo-oxepinyl, dibenzopyranonyl,dibenzoquinoxalinyl, dibenzothiazepinyl, dibenzoisoquinolinyl,tetraazaadamantyl, thiatetraazaadamantyl, oxauracil, oxazinyl,dibenzothiophenyl, dibenzofuranyl, oxazolinyl, oxazolonyl, azaindolyl,azolonyl, thiazolinyl, thiazolonyl, thiazolidinyl, thiazanyl,pyrimidonyl, thiopyrimidonyl, thiamorpholinyl, azlactonyl,naphtindazolyl, naphtindolyl, naphtothiazolyl, naphtothioxolyl,naphtoxindolyl, naphtotriazolyl, naphtopyranyl, oxabicycloheptyl,azabenzimidazolyl, azacycloheptyl, azacyclooctyl, azacyclononyl,azabicyclononyl, tetrahydrofuryl, tetrahydropyranyl, tetrahydropyronyl,tetrahydro-quinoleinyl, tetrahydrothienyl and dioxide thereof,dihydrothienyl dioxide, dioxindolyl, dioxinyl, dioxenyl, dioxazinyl,thioxanyl, thioxolyl, thiourazolyl, thiotriazolyl, thiopyranyl,thiopyronyl, coumarinyl, quinoleinyl, oxyquinoleinyl, quinuclidinyl,xanthinyl, dihydropyranyl, benzodihydrofuryl, benzothiopyronyl,benzothiopyronyl, benzoxazinyl, benzoxazolyl, benzodioxolyl,benzodioxanyl, benzothiadiazolyl, benzotriazinyl, benzothiazolyl,benzoxazolyl, phenothioxinyl, phenothiazolyl, phenothienyl(benzothiofuranyl), phenopyronyl, phenoxazolyl, pyridinyl,dihydropyridinyl, tetrahydropyridinyl, piperidinyl, morpholinyl,thiomorpholinyl, pyrazinyl, pyrimidinyl, pyridazinyl, triazinyl,tetrazinyl, triazolyl, benzotriazolyl, tetrazolyl, imidazolyl,pyrazolyl, thiazolyl, thiadiazolyl, isothiazolyl, oxazolyl, oxadiazolyl,pyrrolyl, furyl, dihydrofuryl, furoyl, hydantoinyl, dioxolanyl,dioxolyl, dithienyl, dithienyl, dithiinyl, thienyl, indolyl, indazolyl,indolinyl, indolizidinyl, benzofuryl, quinolyl, quinazolinyl,quinoxalinyl, carbazolyl, phenoxazinyl, phenothiazinyl, xanthenyl,purinyl, benzothienyl, naphtothienyl, thianthrenyl, pyranyl, pyronyl,benzopyronyl, isobenzofuranyl, chromenyl, phenoxathiinyl, indolizinyl,quinolizinyl, isoquinolyl, phthalazinyl, naphthiridinyl, cinnolinyl,pteridinyl, carbolinyl, acridinyl, perimidinyl, phenanthrolinyl,phenazinyl, phenothiazinyl, imidazolinyl, imidazolidinyl,benzimidazolyl, pyrazolinyl, pyrazolidinyl, pyrrolinyl, pyrrolidinyl,piperazinyl, uridinyl, thymidinyl, cytidinyl, azirinyl, aziridinyl,diazirinyl, diaziridinyl, oxiranyl, oxaziridinyl, dioxiranyl, thiiranyl,azetyl, dihydroazetyl, azetidinyl, oxetyl, oxetanyl, thietyl, thietanyl,diazabicyclooctyl, diazetyl, diaziridinonyl, diaziridinethionyl,chromenyl, chromanonyl, thiochromanyl, thiochromanonyl, thiochromenyl,benzofuranyl, benzisothiazolyl, benzocarbazolyl, benzochromonyl,benzisoalloxazinyl, benzocoumarinyl, thiocoumarinyl, phenometoxazinyl,phenoparoxazinyl, phentriazinyl, thiodiazinyl, thiodiazolyl, indoxyl,thioindoxyl, benzodiazinyl (e.g. phtalazinyl), phtalidyl, phtalimidinyl,phtalazonyl, alloxazinyl, dibenzopyronyl (i.e. xanthonyl), xanthionyl,isatyl, isopyrazolyl, isopyrazolonyl, urazolyl, urazinyl, uretinyl,uretidinyl, succinyl, succinimido, benzylsultimyl, benzylsultamyl andthe like, including all possible isomeric forms thereof, wherein eachcarbon atom of said heterocyclic ring may be independently substitutedwith a substituent selected from the group consisting of halogen, nitro,C₁₋₇ alkyl (optionally containing one or more functions or groupsselected from the group consisting of carbonyl (oxo), alcohol(hydroxyl), ether (alkoxy), acetal, amino, imino, oximino, alkyloximino,amino-acid, cyano, carboxylic acid ester or amide, nitro, thio C₁₋₇alkyl, thio C₃₋₁₀ cycloalkyl, C₁₋₇ alkylamino, cycloalkylamino,alkenylamino, cycloalkenylamino, alkynylamino, arylamino,arylalkylamino, hydroxylalkylamino, mercaptoalkylamino, heterocyclicamino, hydrazino, alkyihydrazino, phenylhydrazino, sulfonyl, sulfonamidoand halogen), C₂₋₇ alkenyl, C₂₋₇ alkynyl, halo C₁₋₇ alkyl, C₃₋₁₀cycloalkyl, aryl, arylalkyl, alkylaryl, alkylacyl, arylacyl, hydroxyl,amino, C₁₋₇ alkylamino, cycloalkylamino, alkenylamino,cyclo-alkenylamino, alkynylamino, arylamino, arylalkylamino,hydroxyalkylamino, mercaptoalkylamino, heterocyclic amino, hydrazino,alkyihydrazino, phenylhydrazino, sulfhydryl, C₁₋₇ alkoxy, C₃₋₁₀cycloalkoxy, aryloxy, arylalkyloxy, oxyheterocyclic,heterocyclic-substituted alkyloxy, thio C₁₋₇ alkyl, thio C₃₋₁₀cycloalkyl, thioaryl, thioheterocyclic, arylalkylthio,heterocyclic-substituted alkylthio, formyl, hydroxylamino, cyano,carboxylic acid or esters or thioesters or amides thereof,thiocarboxylic acid or esters or thioesters or amides thereof; dependingupon the number of unsaturations in the 3 to 10 membered ring,heterocyclic radicals may be sub-divided into heteroaromatic (or“heteroaryl”) radicals and non-aromatic heterocyclic radicals; when aheteroatom of the said non-aromatic heterocyclic radical is nitrogen,the latter may be substituted with a substituent selected from the groupconsisting of C₁₋₇ alkyl, C₃₋₁₀ cycloalkyl, aryl, arylalkyl andalkylaryl.

As used herein with respect to a substituent, ligand or group, andunless otherwise stated, the terms “C₁₋₇ alkoxy”, “C₂₋₇ alkenyloxy”,“C₂₋₇alkynyloxy”, “C₃₋₁₀ cyclo-alkoxy”, “aryloxy”, “arylalkyloxy”,“oxyheterocyclic”, “thio C₁₋₇ alkyl”, “thio C₃₋₁₀ cycloalkyl”,“arylthio”, “arylalkylthio” and “thioheterocyclic” refer to substituentswherein a C₁₋₇ alkyl, C₂₋₇ alkenyl or C₂₋₇ alkynyl (optionally thecarbon chain length of such groups may be extended to 20 carbon atoms),respectively a C₃₋₁₀ cycloalkyl, aryl, arylalkyl or heterocyclic radical(each of them such as defined herein), are attached to an oxygen atom ora divalent sulfur atom through a single bond, such as but not limited tomethoxy, ethoxy, propoxy, butoxy, pentoxy, isopropoxy, sec-butoxy,tert-butoxy, isopentoxy, cyclopropyloxy, cyclobutyloxy, cyclopentyloxy,thiomethyl, thioethyl, thiopropyl, thiobutyl, thiopentyl,thiocyclopropyl, thiocyclobutyl, thiocyclopentyl, thiophenyl, phenyloxy,benzyloxy, mercaptobenzyl, cresoxy and the like.

As used herein with respect to a substituting atom or ligand, the termhalogen means any atom selected from the group consisting of fluorine,chlorine, bromine and iodine.

As used herein with respect to a substituting radical or group, andunless otherwise stated, the term “halo C₁₋₇ alkyl” means a C₁₋₇ alkylradical (such as above defined, i.e. optionally the carbon chain lengthof such group may be extended to 20 carbon atoms) in which one or morehydrogen atoms are independently replaced by one or more halogens(preferably fluorine, chlorine or bromine), such as but not limited tofluoromethyl, difluoromethyl, trifluoromethyl, chloromethyl,dichloromethyl, trichloromethyl, 2,2,2-trifluoroethyl, 2-fluoroethyl,2-chloroethyl, 2,2,2-trichloroethyl, octafluoropentyl,dodecafluoroheptyl, dichloromethyl and the like.

As used herein with respect to a substituent, ligand or group, andunless otherwise stated, the term “C₂₋₇ alkenyl” means a straight orbranched acyclic hydrocarbon monovalent radical having one or moreethylenical unsaturations and having from 2 to 7 carbon atoms such as,for example, vinyl, 1-propenyl, 2-propenyl (allyl), 1-butenyl,2-butenyl, 3-butenyl, 2-pentenyl, 3-pentenyl, 3-methyl-2-butenyl,3-hexenyl, 2-hexenyl, 2-heptenyl, 1,3-butadienyl, n-penta-2,4-dienyl,hexadienyl, heptadienyl, heptatrienyl and the like, including allpossible isomers thereof; optionally the carbon chain length of suchgroup may be extended to 20 carbon atoms (such as n-oct-2-enyl,n-dodec-2-enyl, isododecenyl, n-octadec-2-enyl and n-octadec-4-enyl).

As used herein with respect to a substituent, ligand or group, andunless otherwise stated, the term “C₃₋₁₀ cycloalkenyl” means amonocyclic mono- or polyunsaturated hydrocarbon monovalent radicalhaving from 3 to 8 carbon atoms, such as for instance cyclopropenyl,cyclobutenyl, cyclopentenyl, cyclopentadienyl, cyclohexenyl,cyclohexa-dienyl, cycloheptenyl, cycloheptadienyl, cycloheptatrienyl,cyclooctenyl, cyclooctadienyl, cyclooctatrienyl,1,3,5,7-cyclooctatetraenyl and the like, or a C₇₋₁₀ polycyclic mono- orpolyunsaturated hydrocarbon monovalent radical having from 7 to 10carbon atoms such as dicyclopentadienyl, fenchenyl (including allisomers thereof, such as α-pinolenyl), bicyclo[2.2.1]hept-2-enyl(norbornenyl), bicyclo[2.2.1]hepta-2,5-dienyl (norbornadienyl),cyclofenchenyl and the like.

As used herein with respect to a substituent, ligand or group, the term“C₂₋₇ alkynyl” defines straight and branched chain hydrocarbon radicalscontaining one or more triple bonds (i.e. acetylenic unsaturation) andoptionally at least one double bond and having from 2 to 7 carbon atomssuch as, for example, acetylenyl, 1-propynyl, 2-propynyl, 1-butynyl,2-butynyl, 2-pentynyl, 1-pentynyl, 3-methyl-2-butynyl, 3-hexynyl,2-hexynyl, 1-penten-4-ynyl, 3-penten-1-ynyl, 1,3-hexadien-1-ynyl and thelike, including all possible isomers thereof; optionally the carbonchain length of such group may be extended to 20 carbon atoms.

As used herein with respect to a substituent, ligand or group, andunless otherwise stated, the terms “arylalkyl”, “arylalkenyl” and“heterocyclic-substituted alkyl” refer to an aliphatic saturated orunsaturated hydrocarbon monovalent radical (preferably a C₁₋₇ alkyl orC₂₋₇ alkenyl radical such as defined above, i.e. optionally the carbonchain length of such group may be extended to 20 carbon atoms) ontowhich an aryl or heterocyclic radical (such as defined above) is alreadybonded, and wherein the said aliphatic radical and/or the said aryl orheterocyclic radical may be optionally substituted with one or moresubstituents selected from the group consisting of halogen, amino,nitro, hydroxyl, sulfhydryl and nitro, such as but not limited tobenzyl, 4-chlorobenzyl, phenylethyl, 3-phenylpropyl, α-methylbenzyl,phenbutyl, α,α-dimethylbenzyl, 1-amino-2-phenylethyl,1-amino-2-[4-hydroxyphenyl]ethyl, 1-amino-2-[indol-2-yl]ethyl, styryl,pyridylmethyl, pyridylethyl, 2-(2-pyridyl)isopropyl, oxazolylbutyl,2-thienylmethyl and 2-furylmethyl.

As used herein with respect to a substituent, ligand or group, andunless otherwise stated, the terms “alkylcycloalkyl”,“alkenyl(hetero)aryl”, “alkyl(hetero)aryl” and “alkyl-substitutedheterocyclic” refer respectively to an aryl, heteroaryl, cycloalkyl orheterocyclic radical (such as defined above) onto which are alreadybonded one or more aliphatic saturated or unsaturated hydrocarbonmonovalent radicals, preferably one or more C₁₋₇ alkyl, C₂₋₇ alkenyl orC₃₋₁₀ cycloalkyl radicals as defined above, such as, but not limited to,o-toluyl, m-toluyl, p-toluyl, 2,3-xylyl, 2,4-xylyl, 3,4-xylyl,o-cumenyl, m-cumenyl, p-cumenyl, o-cymenyl, m-cymenyl, p-cymenyl,mesityl, lutidinyl (i.e. dimethylpyridyl), 2-methylaziridinyl,methylbenzimidazolyl, methylbenzofuranyl, methylbenzothiazolyl,methyl-benzotriazolyl, methylbenzoxazolyl, methylcyclohexyl and menthyl.

As used herein with respect to a substituent or group, and unlessotherwise stated, the terms “alkylamino”, “cycloalkylamino”,“alkenylamino”, “cycloalkenylamino”, “arylamino”, “aryl-alkylamino”,“heterocyclic amino”, “hydroxyalkylamino”, “mercaptoalkylamino” and“alkynylamino” mean that respectively one (thus monosubstituted amino)or even two (thus disubstituted amino) C₁₋₇ alkyl, C₃₋₁₀ cycloalkyl,C₂₋₇ alkenyl, C₃₋₁₀ cycloalkenyl, aryl, arylalkyl, heterocyclic, mono-or polyhydroxy C₁₋₇ alkyl, mono- or polymercapto C₁₋₇ alkyl or C₂₋₇alkynyl radical(s) (each of them as defined herein, respectively) is/areattached to a nitrogen atom through a single bond or, in the case ofheterocyclic, include a nitrogen atom, such as but not limited to,anilino, benzylamino, methylamino, dimethylamino, ethylamino,diethylamino, isopropylamino, propenylamino, n-butylamino,ter-butylamino, dibutylamino, morpholinoalkylamino, morpholinyl,piperidinyl, piperazinyl, hydroxymethylamino, β-hydroxyethylamino andethynylamino; this definition also includes mixed disubstituted aminoradicals wherein the nitrogen atom is attached to two such radicalsbelonging to two different sub-set of radicals, e.g. an alkyl radicaland an alkenyl radical, or to two different radicals within the samesub-set of radicals, e.g. methylethylamino; among disubstituted aminoradicals, symetrically substituted are usually preferred and more easilyaccessible.

As used herein, and unless otherwise stated, the terms “(thio)carboxylicacid (thio)ester” and “(thio)carboxylic acid (thio)amide” refer tosubstituents wherein the carboxyl or thiocarboxyl group is bonded to thehydrocarbonyl residue of an alcohol, a thiol, a polyol, a phenol, athiophenol, a primary or secondary amine, a polyamine, an amino-alcoholor ammonia, the said hydrocarbonyl residue being selected from the groupconsisting of C₁₋₇ alkyl, C₂₋₇ alkenyl, C₂₋₇ alkynyl, C₃₋₁₀ cycloalkyl,C₃₋₁₀ cycloalkenyl, aryl, arylalkyl, alkylaryl, alkylamino,cycloalkylamino, alkenylamino, cycloalkenylamino, arylamino,arylalkylamino, heterocyclic amino, hydroxyalkylamino,mercapto-alkylamino or alkynylamino (each such as above defined,respectively).

As used herein with respect to a metal ligand, the terms alkylammoniumand arylammonium mean a tetra-coordinated nitrogen atom being linked toone or more C₁₋₇ alkyl, C₃₋₁₀ cycloalkyl, aryl or heteroaryl groups,each such as above defined, respectively.

As used herein with respect to a metal ligand, and unless otherwisestated, the term “Schiff base” conventionally refers to the presence ofan imino group (usually resulting from the reaction of a primary aminewith an aldehyde or a ketone) in the said ligand, being part of amultidentate ligand (such as defined for instance inhttp://www.ilpi.com/organometicoordnum.html) and which is coordinated tothe metal, in addition to the nitrogen atom of said imino group, throughat least one further heteroatom selected from the group consisting ofoxygen, sulfur and selenium. The said multidentate ligand may be forinstance:

-   -   a N,O-bidentate Schiff base ligand such as a lumazine or        substituted lumazine or 2-(2-hydroxyphenyl)benzoxazole or        (2′-hydroxyphenyl)-2-thiazoline, or    -   a N,S-bidentate Schiff base ligand such as a thiolumazine or        substituted thiolumazine, or    -   a N,Z-bidentate Schiff base ligand such as shown in FIG. 1,        wherein Z is or includes an atom selected from the group        consisting of oxygen, sulfur and selenium; it may be        advantageous for the said bidentate Schiff base ligand to        further include a carbon-carbon double bond conjugated with the        carbon-nitrogen double bond of the imino group, for instance as        shown in FIG. 1, or    -   a N,N,O-tridentate Schiff base ligand such as derived from        6-amino-5-formyl-1,3-dimethyluracil and semicarbazide or        acetylhydrazine or benzoylhydrazine, or such as derived from        7-formyl-8-hydroxyquinoline(oxine) and 2-aminophenol or        2-aminopyridine, or    -   a O,N,O-tridentate Schiff base ligand such as        6-amino-5-formyl-1,3-dimethyluracil-benzoyl-hydrazone or such as        shown in formula (IV) of FIG. 5 or N-(2-methoxyphenyl)        salicylideneamine or salicylaldehyde-2-hydroxanil or the        heterocyclic Schiff base resulting from the reaction of        1-amino-5-benzoyl-4-phenyl-1H pyrimidin-2-one with        2-hydroxynaphtaldehyde or the thenoyltrifluoroaceto antipyrine        Schiff base resulting from the reaction of        thenoyl-trifluoroacetone with 4-aminoantipyrine, or    -   a O,N,S-tridentate Schiff base ligand such as        salicylaldehyde-2-mercaptoanil,        S-benzyl-2[(2-hydroxyphenyl)methylene]dithiocarbazate or        2-[(2-hydroxyphenyl) methylene]-N-phenylhydrazinecarbothioamide,        or    -   a N,N,S-tridentate Schiff base ligand such as        6-amino-5-formyl-1,3-dimethyluracilthio-semicarbazonate.        By extension, the multidentate ligand may include more than one        Schiff base, for instance two imino groups as shown in formulae        (IIA) and (IIB) of FIG. 2 and in formula (IIIA) of FIG. 3, thus        possibly resulting in O,N,N,O-tetradentate or        O,N,N,N-tetradentate Schiff base ligands.

As used herein, the term “heteroatom-containing alkylidene” relates toligands of the formula=CH—Z—R, wherein Z is sulfur,hydrocarbylphosphino, oxygen or hydro-carbylamino, and wherein R ishydrocarbyl, such as described for instance in WO 99/00396.

As used herein, the term “constraint steric hindrance” relates to agroup or ligand, usually a branched or substituted group or ligand,which is constrained in its movements, i.e. a group the size of whichproduces a molecular distortion (either an angular distortion or alengthening of bonds) being measurable by X-ray diffraction.

As used herein and unless otherwise stated, the term “stereoisomer”refers to all possible different isomeric as well as conformationalforms which the compounds of the invention may possess, in particularall possible stereochemically and conformationally isomeric forms, alldiastereomers, enantiomers and/or conformers of the basic molecularstructure. Some compounds of the present invention may exist indifferent tautomeric forms, all of the latter being included within thescope of the present invention.

As used herein and unless otherwise stated, the term “enantiomer” meanseach individual optically active form of a compound of the invention,having an optical purity or enantiomeric excess (as determined bymethods standard in the art) of at least 80% (i.e. at least 90% of oneenantiomer and at most 10% of the other enantiomer), preferably at least90% and more preferably at least 98%.

As used herein and unless otherwise stated, the term “solvate” includesany combination which may be formed by a compound of this invention witha suitable inorganic solvent (e.g. hydrates formed with water) ororganic solvent, such as but not limited to alcohols (in particularethanol and isopropanol), ketones (in particular methyl-ethylketone andmethylisobutylketone), esters (in particular ethyl acetate) and thelike.

DETAILED DESCRIPTION OF THE INVENTION

In its broadest meaning, the present invention first relates to a methodof modifying a multi-coordinated metal complex, a salt, a solvate or anenantiomer thereof, said multi-coordinated metal complex preferablycomprising (i) at least one multidentate Schiff base ligand comprisingan imino group and being coordinated to the metal, in addition to thenitrogen atom of said imino group, through at least one furtherheteroatom selected from the group consisting of oxygen, sulfur andselenium, and (ii) one or more other ligands, under conditions such thatat least partial cleavage of a bond between the metal and themultidentate Schiff base ligand of said multi-coordinated metal complexoccurs. The metal complex modification occurs by reaction with anactivating compound, and may further optionally include:

-   -   either the coordination of the nitrogen atom of said Schiff base        to the activating compound,    -   or the protonation of said multidentate Schiff base ligand,        optionally followed by decoordination of said further heteroatom        of said multidentate Schiff base ligand from the complexed        metal,    -   or both.

In order to achieve this result, i.e. in order to effectively modify thestructure of a starting multi-coordinated metal complex and preferablyin order to modify said structure in such a way that the catalyticefficiency of the modified metal complex is higher than the catalyticefficiency of the starting non-modified metal complex in a given organicreaction such as the metathesis of unsaturated organic compounds, theactivating compound must be suitably selected. According to the firstaspect of the present invention, the activating compound must beselected within the groups of metal or silicon activating compoundsdescribed hereinabove in the summary of the invention together withreference to specific formulae. For practical reasons it is preferred touse such compounds that are commercially available and, when suchcompounds are solid at room temperature, to use solutions of suchcompounds in suitable organic solvents such as, but not limited to,ethers (e.g. diethyl ether or tetrahydrofuran), alcanes, aromatichydrocarbons (e.g. toluene), esters (e.g. alkyl acetates), halogenatedhydrocarbons and the like. Also for practical reasons for further use ofthe modified metal complex in organic synthesis reactions such as themetathesis of unsaturated compounds (e.g. olefins and alkynes), it ispreferred that said organic solvents be the same as, or at leastmiscible with the organic solvent, if any, to be used for performingsaid organic synthesis reactions. The skilled person can readilydetermine, from general literature (such as the Handbook of Chemistryand Physics (e.g. 61^(st) edition, 1980) or from standard solubilitytests, which solvents are most appropriate for each individualactivating compound.

Copper (I) halides suitable as activating compounds in this inventioninclude, but are not limited to, copper (I) bromide, copper (I)chloride, copper (I) fluoride, copper (I) iodide and copper (I)fluosilicate Cu₂SiF₆.

Zinc compounds suitable as activating compounds in the first aspect ofthis invention include, but are not limited to, di-n-butylzinc,diethylzinc, dimethyizinc, diphenyizinc, di-n-propylzinc, di-o-tolylzincand zinc bromide, zinc chloride, zinc fluoride and zinc iodide.

Tin compounds suitable as activating compounds in the first aspect ofthis invention include, but are not limited to, di-n-butyltin dibromide,di-n-butyltin dichloride, di-tert-butyltin dichloride, dimethyltindibromide, dimethyltin dichloride, dimethyltin difluoride, dimethyltindiiodide, diphenyltin dichloride, diphenyltin dibromide, diphenyltindifluoride, diphenyltin diiodide, tributyltin fluoride, tributyltinchloride, tributyltin bromide, tributyltin iodide, phenyltin tribromide,phenyltin trichloride, tricyclohexyltin chloride, triethyltin bromide,triethyltin chloride, triethyltin iodide, vinyltributyltin,tetrabutyltin, tin (IV) bromide, tin bromide trichloride, tin dibromidedichloride, tin tribromide chloride, tin dibromide, diiodide, tin (IV)chloride, tin trichloride bromide, tin dichloride diiodide, tin (IV)fluoride, tin (IV) iodide, butyltin trichloride, n-butylvinyltindichloride, diallyldibutyltin, diallyldiphenyltin, dibutylvinyltinbromide, dibutylvinyltin chloride, dichlorodi-m-tolylstannane,diethyldiisoamyltin, diethyldiisobutyltin, diethyldiphenyltin,diethylisoamyltin bromide, diethylisoamyltin chloride,diethylisobutyltin bromide, diethyl-n-propyltin bromide,diethyl-n-propyltin chloride, diethyl-n-propyltin fluoride, diethyltindibromide, diethyltin dichloride, diethyltin difluoride, diethyltindiiodide, diisoamyltin dibromide, diisoamyltin dichloride, diisoamyltindiiodide, diisobutyltin dichloride, diisobutyltin diiodide,diisopropyltin dichloride, diisopropyltin dibromide, dimethyldiethyltin,dimethyldiisobutyltin, dimethyldioctyltin, dimethyldivinyltin,dimethylethylpropyltin, dimethylethyltin iodide, dimethyldivinyltin,dimethylvinyltin bromide, dimethylvinyltin iodide, diphenyldivinyltin,dipropyltin difluoride, dipropyltin diiodide, dipropyltin dichloride,dipropyltin dibromide, di-o-tolyltin dichloride, di-p-tolyltindichloride, ditriphenyl-stannylmethane, divinylbutyltin chloride,divinyltin dichloride, ethyldiisoamyltin bromide, ethyldiisobutyltinbromide, ethylmethylpropyltin iodide, ethyl-n-propyldiisoamyltin,ethylpropyltin dichloride, ethyltin tribromide, ethyltin triiodide,ethyltri-n-butyltin, ethyltri-n-propyltin, methyltin tribromide,methyltin trichloride, methyltin triiodide, methyltri-n-butyltin,methyltri-n-propyltin, phenylbenzyltin dichloride, phenyltribenzyltin,propyltin triiodide, propyltri-n-amyltin, tetra-n-amyltin,tetra-n-butyltin, tetrabenzyltin, tetracyclohexyltin, tetraethyltin,tetra-n-heptyltin, tetra-n-hexyltin, tetraisoamyltin, tetraisobutyltin,tetralauryltin, tetramethyltin, tetra-n-octyltin, tetraphenyltin,tetrapropyltin, tetra-o-tolyltin, tetra-m-tolyltin, tetra-p-tolyltin,tetravinyltin, tetra-m-xylyltin, tetra-p-xylyltin, o-tolyltintrichloride, p-tolyltin trichloride, m-tolyltrichlorostannane,triallylbutyltin, tri-n-amyltin bromide, tribenzylethyltin, tribenzyltinchloride, tribenzyltin iodide, tri-n-butyltin bromide,tri-n-butylvinyltin, triethyl-n-amyltin, triethylisoamyltin,triethylisobutyltin, triethylphenyltin, triethyl-n-propyltin,triisoamyltin bromide, triisoamyltin chloride, triisoamyltin fluoride,triisoamyltin iodide, triisobutylethyltin, triisobutylisoamyltin,triisobutyltin bromide, triisobutyltin chloride, triisobutyltinfluoride, triisobutyltin iodide, triisopropyltin bromide,triisopropyltin iodide, trimethyldecyltin, trimethyldodecyltin,trimethylethyltin, trimethyltin bromide, trimethyltin chloride,trimethyltin fluoride, trimethyltin iodide, triphenylallyltin,triphenylbenzyltin, triphenylbutyltin, triphenylethyltin,triphenylmethyltin, triphenyl-α-naphthyltin, triphenyltin bromide,triphenyltin chloride, triphenyltin fluoride, triphenyltin iodide,triphenyl-p-tolyltin, triphenyl-p-xylyltin, tri-n-propyl-n-butyltin,tri-n-propylethyltin, tri-n-propylisobutyl tin, tri-n-propyltinchloride, tri-n-propyltin fluoride, tri-n-propyltin iodide,tri-o-tolyltin bromide, tri-p-tolyltin bromide, tri-o-tolyltin chloride,tri-m-tolyltin chloride, tri-p-tolyltin chloride, tri-p-tolyltinfluoride, tri-o-tolyltin iodide, tri-p-tolyltin iodide,triphenylstannylmethane, trivinyldecyltin, trivinyihexyltin,trivinyloctyltin, trivinyltin chloride, vinyltin trichloride,tri-p-xylyltin bromide, tri-p-xylyltin chloride, tri-p-xylyltinfluoride, tri-p-xylyltin iodide and tri-m-xylyltin fluoride.

Silicon compounds suitable as activating compounds in the first aspectof this invention include, but are not limited to, bromosilane,dibromosilane, bromotrichlorosilane, dibromodichlorosilane,chlorosilane, dichlorosilane, dichlorodifluorosilane, trichlorosilane,trichloroiodosilane, trifluorosilane, triiodosilane, iodosilane,dimethylhexylsilyl chloride, dimethylphenylsilane, dimethylethylsilane,diethylmethylsilane, dichlorodiphenylsilane, diphenylmethylsilane,diphenylsilane, dichlorodiethylsilane, methylsilane,methyltriphenyl-silane, tetraphenylsilane, tributylsilane,tetraethylsilane, tetramethylsilane, silicon tetrachloride,ethyltrichloro-silane, octyltrichlorosilane, octadecyltrichlorosilane,phenyl-trichlorosilane, triethylsilane, triethyifluorosilane,triethylvinylsilane, triisobutylsilane, triisopropylsilane,triisopropylsilyl chloride, vinyltrichlorosilane, vinyltrimethylsilane,chlorotrimethylsilane, bromotrimethylsilane,2-trimethylsilyl-1,3-dithiane, iodotrimethyl-silane,chlorodimethylethylsilane, chlorodimethylisopropylsilane,chlorodimethyloctadecyl-silane, chlorodimethyloctylsilane,chlorodimethylphenylsilane, chlorocyclohexyldimethyl-silane,butyltrifluorosilane, chloro(3-cyanopropyl)dimethylsilane,chloro(chloromethyl)-dimethylsilane, (chloromethyl)trichlorosilane andchlorodimethylpentafluorophenylsilane.

According to the second aspect of the invention, the activating compoundmust include at least one halogen atom directly bonded to at least oneatom having an atomic mass from 27 to 124 and being selected from thegroup consisting of groups IB, IIB, IIIA, IVB, IVA and VA of thePeriodic Table of elements. Preferred such atoms include aluminium(atomic mass 27), silicium (atomic mass 28), phosphorus (atomic mass31), titanium (atomic mass 48), copper (atomic mass 63), zinc (atomicmass 65), and tin (atomic mass 119 or 124). Other suitable atoms includeantimony, germanium, cadmium, silver, indium and zirconium.

When such atom having an atomic mass from 27 to 124 is copper, it may beany copper (I) halide as described herein with respect to the firstaspect of the invention.

When such atom having an atomic mass from 27 to 124 is zinc, it may beany zinc halide as described herein with respect to the first aspect ofthe invention.

When such atom having an atomic mass from 27 to 124 is tin or silicon,it may be any tin compound or silicon compound as described herein withrespect to the first aspect of the invention, provided that said tincompound or silicon compound includes at least a halogen atom. Inparticular it may be any tin compound represented by the structuralformula SnR₉R₁₀R₁₁R₁₂ wherein each of R₉, R₁₀, R₁₁ and R₁₂ isindependently selected from the group consisting of halogen, C₁₋₂₀alkyl, C₃₋₁₀ cycloalkyl, aryl, benzyl and C₂₋₇ alkenyl, provided that atleast one of R₉, R₁₀, R₁₁ and R₁₂ is halogen. It may also be any siliconcompound represented by the structural formula SiR₁₃R₁₄R₁₅R₁₆ whereineach of R₁₃, R₁₄, R₁₅ and R₁₆ is independently selected from the groupconsisting of hydrogen, halogen, C₁₋₂₀ alkyl, halo C₁₋₇ alkyl, aryl,heteroaryl and vinyl, provided that at least one of R₁₃, R₁₄, R₁₅ andR₁₆ is halogen.

Titanium compounds suitable as activating compounds in the second aspectof this invention include titanium tetrahalides such as titaniumtetrachloride and titanium tetrabromide, and titanium trichloride.

Phosphorous compounds suitable as activating compounds in the secondaspect of this invention include phosphorous halides, oxyhalides andthiohalides such as, but not limited to, phosphorous pentabromide,tribromide, dibromide trichloride, monobromide tetrachloride,pentachloride, trichloride, dichloride trifluoride, trichloridediiodide, pentafluoride, trifluoride, triiodide, oxybromide,oxychloride, oxyfluoride, thiobromide and thiochloride.

Aluminium compounds suitable as activating compounds in the secondaspect of this invention may be represented by the structural formulaAlR₁₇R₁₈R₁₉ wherein each of R₉, R₁₇, R₁₈ and R₁₉ is independentlyselected from the group consisting of halogen, hydrogen and C₁₋₇ alkyl,provided that at least one of R₁₇, R₁₈ and R₁₉ is halogen. Non limitingexamples include aluminium halides such as bromide, chloride, fluorideand iodide; dialkylaluminum halides such as diethylaluminum chloride anddimethylaluminum chloride; and alkylaluminum dihalides such asmethylaluminium dichloride.

Other compounds suitable as activating compounds in the second aspect ofthis invention include, but are not limited to:

-   -   antimony compounds such as antimony oxychloride, triethyl        antimony dichloride, and triphenyl antimony dichloride; and    -   germanium compounds which may be represented by the structural        formula GeR₂₀R₂₁R₂₂R₂₃ wherein each of R₂₀, R₂₁, R₂₂ and R₂₃ is        independently selected from the group consisting of halogen,        C₁₋₇ alkyl, aryl and arylalkyl, provided that at least one of        R₂₀, R₂₁, R₂₂ and R₂₃ is halogen.

In order to achieve the desired metal complex modification, not only theactivating compound must be suitably selected but also it is importantto properly select its molar ratio to the multi-coordinated metalcomplex to be modified, as well as the other operating conditions of themodification reaction. Preferably, said conditions independently includeone or more of the following:

-   -   a molar ratio between said activating compound and the metal of        said multi-coordinated metal complex being above about 5:1,        preferably above about 10:1, more preferably above about 20:1,        for instance at least about 30:1;    -   a molar ratio between said activating compound and the metal of        said multi-coordinated metal complex being not above about        2000:1, preferably not above about 500:1, and more preferably        not above about 250:1;    -   a contact time above 5 seconds, preferably above 30 seconds,        more preferably at least 1 minute, for example at least 5        minutes;    -   a contact time below 100 hours, preferably not above 24 hours,        more preferably not above 4 hours, and most preferably not above        2 hours;    -   a contact temperature from about −50° C. to about 80° C.,        preferably from about 10° C. to about 60° C., more preferably        from about 20° C. to about 50° C.

According to a first embodiment of this invention, the activatingcompound is used as the single species for modifying a multi-coordinatedmetal complex (or a salt, a solvate or an enantiomer thereof). As willbe understood from the following description, this means that when theactivating compound includes at least one halogen atom, it is not usedin the presence of an additive such as water, an organic acid, analcohol or a phenol that can abstract said halogen atom and replace theactivating compound with another activating species. Such additives tobe avoided for performing the first embodiment of this inventioninclude, but are not limited to:

-   -   impurities of the solvent that may be used for performing a        metathesis reaction in the presence of the multi-coordinated        metal complex,    -   impurities of the unsaturated compound that may be submitted to        a metathesis reaction in the presence of the multi-coordinated        metal complex, and    -   additives (e.g. antioxidants) deliberately present in the        unsaturated compound that may be submitted to a metathesis        reaction in the presence of the multi-coordinated metal complex.

According to a second embodiment of this invention, the metal complexmodification takes place in the further presence of a reactant being anorganic acid or having the formula RYH, wherein Y is selected from thegroup consisting of oxygen, sulfur and selenium, preferably Y is oxygen,and R is selected from the group consisting of hydrogen, aryl,heteocyclic, heterocyclic-substituted alkyl, arylalkyl, C₂₋₇ alkenyl andC₁₋₇ alkyl. In order for this specific embodiment to provide additionaluseful effect over the embodiment without said further reactant,especially by forming in situ a strong acid (such as a hydrogen halide)by the reaction of the activating compound with said further reactant(e.g. a reactant having the formula RYH), it is however necessary forthe activating compound to include at least one halogen atom. Thefurther reactant present in this embodiment of the invention thus has atleast one labile hydrogen atom, such as water, monocarboxylic acids,monohydric alcohols and phenols, but may also have more than one labilehydrogen atom, such as polycarboxylic acids (in particular dicarboxylicacids), polyhydric alcohols, alcohols/phenols and polyphenols. Sincewater is also a further reactant according to this embodiment of theinvention, it is not necessary for these mono- or polycarboxylic acids,monohydric or polyhydric alcohols, phenols or polyphenols to be used instrictly anhydrous grades but it is admissible to use them in the formof commercial grades including traces of water. Preferably the furtherreactant has no other functional group that may negatively interact withthe hydrogen halide formation process, e.g. by providing the possibilityfor a competitive reaction with the halogen atom of the activatingcompound and thus slowing down the rate of the desired hydrogen halideformation. Therefore it may be important to purify a commercial grade ofthe further reactant when it is known or suspected to contain asignificant amount of at least one impurity having such negativelyinteracting functional group. For practical reasons it is preferred touse reactants that are commercially available and, when such reactantsare solid at room temperature, to use solutions of such reactants insuitable organic solvents such as, but not limited to, ethers (e.g.diethyl ether or tetrahydrofuran), alcanes, aromatic hydrocarbons (e.g.toluene) and the like. Also for practical reasons for further use of themodified metal complex in organic synthesis reactions such as themetathesis of unsaturated compounds (e.g. olefins and alkynes), it ispreferred that said organic solvents be the same as, or at leastmiscible with the organic solvent, if any, to be used for performingsaid organic synthesis reactions. The skilled person can readilydetermine, from general literature (such as the Handbook of Chemistryand Physics (e.g. 61^(st) edition, 1980) or from standard solubilitytests, which solvents are most appropriate for each individual furtherreactant.

Representative examples of suitable reactants of this type thus include,but are not limited to, the following:

-   -   C₁₋₇ alkyl monoalcohols such as methanol, ethanol, isopropanol,        n-propanol, isobutanol, n-butanol, tert-butanol, pentanol,        2,2-dimethyl-3-pentanol, 2,3-dimethyl-3-pentanol,        2,4-dimethyl-3-pentanol, 4,4-dimethyl-2-pentanol,        2,2-dichloroethanol, 1,3-dibromo-2-propanol,        2,3-dibromopropanol, 1,3-dichloro-2-propanol,        1,3-dichloro-2-propanol, 2-chloroethanol,        2-(2-chloroethoxy)ethanol, 2-[(2-chloroethoxy)ethoxy]-ethanol,        6-chloro-1-hexanol, 2-chloromethyl-2-methyl-1-propanol,        1-bromo-2-propanol, 3-bromo-1-propanol, 3-methyl-1-butanol,        2,2,2-tribromoethanol, 2,2,2-trifluoroethanol,        2,2,2-trichloroethanol, 2,2,3,3,3-pentafluoro-1-propanol,        2,2,3,3,4,4,4-heptafluoro-1-butanol, 1-heptanol and 2-heptanol;    -   C₂₋₇ alkenyl monoalcohols such as 3-methyl-3-buten-1-ol, allyl        alcohol, 3-buten-1-ol, 3-buten-2-ol, 1-hexen-3-ol, 2-hexen-1-ol,        4-hexen-1-ol, 5-hexen-1-ol and the like;    -   C₂₋₇ alkenyl polyalcohols such as 2-butene-1,4-diol and the        like,

C₁₋₇ alkyl polyalcohols such as ethanediol, 1,2-propanediol,1,2-propanediol, 1,2-butane-diol, 1,3-butanediol, 1,4-butanediol,2,3-butanediol, 2,4-dimethyl-2,4-pentanediol, 3-bromo-1,2-propanediol,1,2-pentanediol, 1,4-pentanediol, 1,5-pentanediol, 1,5-hexanediol,1,6-hexanediol, 2,5-hexanediol, 1,7-heptanediol, 1,2,4-butanetriol,1,2,6-hexanetriol, mannitol and 1,2,3-heptanetriol;

-   -   arylalkyl monoalcohols such as benzyl alcohol,        2,4-dichlorobenzyl alcohol, 2,5-dichlorobenzyl alcohol,        2,6-dichlorobenzyl alcohol, 3,4-dichlorobenzyl alcohol,        3,5-dichlorobenzyl alcohol, 2,3-difluorobenzyl alcohol,        2,4-difluorobenzyl alcohol, 2,5-difluorobenzyl alcohol,        2,6-difluorobenzyl alcohol, 3,4-difluorobenzyl alcohol,        3,5-difluorobenzyl alcohol, 4,4′-difluorobenzhydrol,        2-chloro-6-fluorobenzyl alcohol, 4-bromophenethyl alcohol,        4-chlorophenethyl alcohol, 3-chlorophenethyl alcohol,        2-chlorophenethyl alcohol, 2-bromobenzyl alcohol, 3-bromobenzyl        alcohol, 4-bromobenzyl alcohol, 4-isopropylbenzyl alcohol,        2,3,4,5,6-pentafluorobenzyl alcohol, and phenethyl alcohol;    -   phenols such as phenol, 2-benzylphenol, 4-benzylphenol,        4,4′-thiodiphenol, 3,3′-thiodipropanol, 2,2′-thiodiethanol,        4-hydroxythiophenol, 2,3-dimethylphenol, 2,4-dimethylphenol,        2,5-dimethylphenol, 2,6-dimethylphenol, 3,4-dimethylphenol,        3,5-dimethylphenol, 2,6-di-tert-butyl-4-sec-butylphenol,        2,4-dibromophenol, 2,6-dibromophenol, 2,3-dichlorophenol,        2,4-dichiorophenol, 2,5-dichlorophenol, 2,6-dichlorophenol,        3,4-dichlorophenol, 3,5-dichlorophenol, 2,3-difluorophenol,        2,4-difluorophenol, 2,5-difluorophenol, 2,6-difluorophenol,        3,4-difluorophenol, o-cresol, m-cresol, p-cresol,        2-fluorophenol, 3-fluorophenol, 4-fluorophenol,        2-chloro-4-fluorophenol, 3-chloro-4-fluorophenol,        4-chloro-2-fluorophenol, 4-chloro-3-fluorophenol,        2-chloro-4-methylphenol, 2-chloro-5-methylphenol,        4-chloro-2-methylphenol, 4-chloro-3-methylphenol,        2-chlorophenol, 3-chlorophenol, 4-chlorophenol, 2-bromophenol,        3-bromophenol, 4-bromophenol, 2-sec-butylphenol,        2-tert-butylphenol, 3-tert-butylphenol, 4-tert-butylphenol,        4-sec-butylphenol, 2-tert-butyl-4-methylphenol,        2-tert-butyl-5-methylphenol, 2-tert-butyl-6-methylphenol,        2-isopropylphenol, 3-isopropylphenol, 4-isopropylphenol,        4-isopropyl-3-methylphenol, 5-isopropyl-3-methylphenol,        5-isopropyl-2-methylphenol, 2-isopropoxyphenol,        2,4,6-trimethylphenol, pentafluoro-phenol, pentachlorophenol,        2,3,4-trichlorophenol, 2,3,5-trichlorophenol,        2,4,5-trichlorophenol, 2,4,6-trichlorophenol,        2,3,6-trichlorophenol, 2,4,6-tribromophenol,        2,3,5-trifluorophenol, 2-trifluoromethylphenol,        3-trifluoromethylphenol, 1-naphthol, 2-naphthol and        4-trifluoromethylphenol;    -   alcohols/phenols such as 2-hydroxybenzyl alcohol,        3-hydroxybenzyl alcohol, 4-hydroxybenzyl alcohol,        2-hydroxy-3-methoxybenzyl alcohol, 3-hydroxy-4-methoxybenzyl        alcohol, 4-hydroxy-3-methoxybenzyl alcohol,        3-(4-hydroxyphenyl)-1-propanol, 2-hydroxyphenethyl alcohol,        3-hydroxyphenethyl alcohol, 2-(2-hydroxyethoxyl)phenol and        4-hydroxyphenethyl alcohol;    -   heterocyclic-substituted alkyl alcohols such as        4-(2-hydroxyethyl)morpholine, 1-(2-hydroxyethyl)pyrrolidine,        1-piperidineethanol, 2-piperidineethanol, 4-piperidineethanol,        2-piperidinemethanol, 3-piperidinemethanol,        1-(2-hydroxyethyl)piperazine and 2-(2-hydroxyethyl)pyridine;    -   heterocyclic-substituted alcohols such as        3-hydroxy-1-methylpiperidine, 4-hydroxy-1-methylpiperidine,        2-hydroxy-6-methylpyridine, 5-hydroxy-2-methyl pyridine,        2-hydroxypyridine, 3-hydroxypyridine, 4-hydroxypyridine and        3-hydroxytetrahydrofuran;    -   monocarboxylic aliphatic or aromatic acids or anhydrides such        as, but not limited to, acetic acid, tribromoacetic acid,        trifluoroacetic acid, trifluoroacetic anhydride, propa-noic        acid, butanoic acid, acetic anhydride, benzoic acid,        trichlorobenzoic acid, trifluorobenzoic acid, naphthoic acid,        and the like; and    -   dicarboxylic aliphatic or aromatic acids or anhydrides such as,        but not limited to, phthalic acid, phthalic anhydride,        tetrahydrophthalic anhydride, maleic acid, maleic anhydride, and        the like.

Within each above sub-class of suitable reactants, it may be importantto pay attention to steric hindrance around the reactive carboxylicacid, alcohol or phenol group, since it is known that bulky groups suchas, but not limited to, tert-butyl in the neighbourhood of saidcarboxylic acid, alcohol or phenol group may significantly reducereactivity with the activating compound and, consequently, maysignificantly reduce the reaction rate of the metal complexmodification, thus in turn resulting in slower reactivity with theunsaturated compound (such as olefin or alkyne) that is submitted to ametathesis reaction in the presence of the modified multicoordinatedmetal complex. This parameter may be suitably used in two ways:

-   -   when the unsaturated compound is highly reactive under the        selected reaction conditions and thus involves a risk of loosing        control of the reaction, it may be appropriate to select a        strongly sterically hindered further reactant such as        2-tert-butylphenol, 2,6-di-tert-butyl-4-sec-butylphenol and the        like, or    -   when the unsaturated compound is hardly reactive under the        selected reaction conditions, it may be appropriate to promote        the desired reaction by avoiding sterically hindered further        reactants or even linear or unsubstituted reactants.

In order to achieve the desired metal complex modification of thissecond embodiment of the invention, not only the further reactant mustbe suitably selected according to the above recommendations but also itis important to properly select its molar ratio to the activatingcompound, as well as the other operating conditions of the modificationreaction. Preferably, said conditions include one or more of thefollowing:

-   -   a molar ratio between said further reactant and said metal or        silicon activating compound being such that each labile hydrogen        atom of the further reactant (e.g. RYH or an organic acid) is        able to react with each halogen atom of the metal or silicon        activating compound; i.e. the suitable molar ratio depends upon        the number of halogen atoms in the metal or silicon activating        compound (which may be 1 when said activating compound is a        copper (I) halide, 2 when said activating compound is a zinc        compound, and from 1 to 4 when said activating compound is a        silicon compound or a tin compound) and depends upon the number        of labile hydrogen atoms in the further reactant (which may be 1        when said further reactant is a monocarboxylic acid, a phenol, a        C₁₋₇ alkyl monoalcohol or an arylalkyl monoalcohol, or which may        be 2 or more when said further reactant is a polycarboxylic        acid, an alcohol/phenol or a C₁₋₇ alkyl polyalcohol), thus a        significant number of situations is likely to appear but in any        situation the skilled is able to easily determine the proper        molar ratio between the two reactive species that will provide a        halogen hydride in situ;    -   a contact time and/or a contact temperature similar to those        specified in the previous embodiment of this invention.

It should be understood that any combination of the above reactionconditions is contemplated as being within the framework of the presentinvention, and that the more suitable conditions depend upon theactivating compound used and optionally upon the set of ligands aroundthe metal center, especially upon the Schiff base ligand, but the moresuitable combination of reaction parameters can easily be determined bythe skilled person while performing standard optimizationexperimentation, based on the information contained therein.

Certain phenols, in particular substituted phenols such as2,6-di-tert-butyl-4-sec-butylphenol, are frequently used as antioxidantsin commercial grades of some unsaturated compounds (such as olefins oralkynes) that may be submitted to a metathesis reaction in the presenceof a modified multicoordinated metal complex according to thisinvention. In such a situation, the second embodiment of the inventionis necessarily applicable and it is advisable to determine the exactamount of such substituted phenols being present in the unsaturatedcompound in order to calculate the suitable amount of activatingcompound to be used, taking into account the desired molar ratio betweenthe reactive phenol and the activating compound, as well as the amountof the multicoordinated metal complex to be used as a catalyst for themetathesis reaction.

In the broadest meaning of the invention, the multicoordinated metalcomplex to be modified is not critical but preferably includes (i) atleast one multidentate Schiff base ligand comprising an imino group andbeing coordinated to the metal, in addition to the nitrogen atom of saidimino group, through at least one further heteroatom selected from thegroup consisting of oxygen, sulfur and selenium, and (ii) one or moreother ligands. When the second embodiment of the invention isapplicable, said other ligands (ii) are preferably not selected from thegroup consisting of amines, phosphines, arsines and stibines, since allof the latter are able of protonation by a hydrogen halide under theabove reaction conditions.

For the performance of the method of the invention, with respect to thedefinition of the ligands coordinating the metal center, the latter isnot a critical parameter but it is suitable when at least one of thefollowing situations occurs:

-   -   at least one of said other ligands (ii) is a constraint steric        hindrance ligand having a pKa of at least 15,    -   the number of carbon atoms in said at least one multidentate        Schiff base ligand (i), between the nitrogen atom of said imino        group and said coordinating heteroatom of said at least one        multidentate Schiff base ligand (i), is 2 or 3,    -   the nitrogen atom of the imino group of the multidentate Schiff        base ligand (i) is substituted with a group having substantial        steric hindrance such as tert-butyl, substituted phenyl (e.g.        mesityl or 2,6-dimethyl-4-bromophenyl) or C₃₋₁₀ cycloalkyl (e.g.        adamantyl),    -   at least one of said other ligands (ii) is a carbene ligand,        preferably selected from the group consisting of N-heterocyclic        carbene ligands, alkylidene ligands, vinylidene ligands,        indenylidene ligands, heteroatom-containing alkylidene ligands,        and allenylidene ligands,    -   at least two of said other ligands (ii) are carbene ligands,        preferably including one selected from the group consisting of        alkylidene ligands, vinylidene ligands, indenylidene ligands,        heteroatom-containing alkylidene ligands and allenylidene        ligands, and a second one being a N-heterocyclic carbene ligand,    -   at least one of said other ligands (ii) is an anionic ligand,    -   at least one of said other ligands (ii) is a non-anionic ligand,        e.g. one other than a carbene ligand.

It should be understood that any combination of the above conditions iscontemplated as being within the framework of the present invention, andthat the more suitable conditions can easily be determined by theskilled person based on the general knowledge in the art and oninformation contained therein. Apart from the above-stated exception foramines, phosphines, arsines and stibines, usually the number and kind ofsaid other ligands (ii) does not play a significant role in thefeasability or efficiency of the metal complex modification according tothe invention.

In a second aspect, the present invention relates to a reaction productof:

-   (a) a multi-coordinated metal complex, a salt, a solvate or an    enantiomer thereof, said multi-coordinated metal complex    comprising (i) at least one multidentate Schiff base ligand    comprising an imino group and being coordinated to the metal, in    addition to the nitrogen atom of said imino group, through at least    one further heteroatom selected from the group consisting of oxygen,    sulfur and selenium, and (ii) one or more other ligands, and-   (b) an activating metal or silicon compound selected from the group    consisting of:    -   copper (I) halides,    -   zinc compounds represented by the formula Z_(n)(R₅)₂, wherein R₅        is halogen, C₁₋₇ alkyl or aryl,    -   aluminum compounds represented by the formula AlR₆R₇R₈ wherein        each of R₆, R₇ and R₈ is independently selected from the group        consisting of halogen and C₁₋₇ alkyl,    -   tin compounds represented by the formula SnR₉R₁₀R₁₁R₁₂ wherein        each of R₉, R₁₀, R₁₁ and R₁₂ is independently selected from the        group consisting of halogen, C₁₋₂₀ alkyl, C₃₋₁₀ cycloalkyl,        aryl, benzyl and C₂₋₇ alkenyl, and    -   silicon compounds represented by the formula SiR₁₃R₁₄R₁₅R₁₆        wherein each of R₁₃, R₁₄, R₁₅ and R₁₆ is independently selected        from the group consisting of hydrogen, halogen, C₁₋₂₀ alkyl,        halo C₁₋₇ alkyl, aryl, heteroaryl and vinyl.

Such a reaction product is the direct result of the metal complexmodification method of the first aspect (especially its first embodimentand its second embodiment) of the invention, and suitable activatingmetal or silicon compounds (b) are as described herein-above withrespect to said modification method. The direct result of the metalcomplex modification method of the second embodiment of the invention isa reaction product of:

-   -   said multi-coordinated metal complex (a),    -   an activating metal or silicon compound (b) including at least        one halogen atom, and    -   (c) a reactant being an organic acid (such as defined        hereinabove) or having the structural formula RYH, wherein Y is        selected from the group consisting of oxygen, sulfur and        selenium, preferably Y is oxygen, and R is selected from the        group consisting of hydrogen, aryl, heteocyclic,        heterocyclic-substituted alkyl, arylalkyl and C₁₋₇ alkyl.

In the latter situation, it is preferred that said one or more otherligands (ii) of the multi-coordinated metal complex (a) are selectedsuch as to be unable of protonation by a hydrogen halide, i.e. are notselected from the group consisting of amines, phosphines, arsines andstibines.

For a more detailed definition of the reaction product according to thisaspect of the invention, it is preferred when at least one of thefollowing situations occurs:

-   -   the pKa of said at least one multidentate Schiff base ligand (i)        is higher than the pKa of the hydrogen halide resulting from the        reaction of (b) and (c),    -   the number of carbon atoms in said at least one multidentate        Schiff base ligand (i), between the nitrogen atom of said imino        group and said heteroatom of said at least one multidentate        Schiff base ligand (i), is 2 or 3,    -   at least one of said other ligands (ii) of said        multi-coordinated metal complex (a) is a constraint steric        hindrance ligand having a pKa of at least 15,    -   the nitrogen atom of the imino group of the multidentate Schiff        base ligand (i) is substituted with a group having substantial        steric hindrance such as tert-butyl, substituted phenyl (e.g.        mesityl or 2,6-dimethyl-4-bromophenyl) or C₃₋₁₀ cycloalkyl (e.g.        adamantyl),    -   at least one of said other ligands (ii) of said        multi-coordinated metal complex (a) is a carbene ligand,        preferably being selected from the group consisting of        N-heterocyclic carbene ligands, alkylidene ligands, vinylidene        ligands, indenylidene ligands, heteroatom-containing alkylidene        ligands and allenylidene ligands,    -   at least two of said other ligands (ii) are carbene ligands,        preferably including one selected from the group consisting of        alkylidene ligands, vinylidene ligands, indenylidene ligands,        heteroatom-containing alkylidene ligands and allenylidene        ligands, and a second one being a N-heterocyclic carbene ligand,    -   at least one of said other ligands (ii) of said        multi-coordinated metal complex (a) is an anionic ligand,    -   at least one of said other ligands (ii) of said        multi-coordinated metal complex (a) is a non-anionic ligand,        e.g. one other than a carbene ligand,    -   said multi-coordinated metal complex (a) is a bimetallic complex        (the two metals being the same or being different), in which        case preferably (1) one metal of said bimetallic complex is        penta-coordinated with said at least one multidentate Schiff        base ligand (i) and with said one or more other ligands (ii),        and the other metal is tetra-coordinated with one or more        neutral ligands and one or more anionic ligands, or (2) each        metal of said bimetallic complex is hexa-coordinated with said        at least one multidentate Schiff base ligand (i) and with said        one or more other ligands (ii);    -   said multi-coordinated metal complex (a) is a monometallic        complex,    -   the metal of said multi-coordinated metal complex (a) is a        transition metal selected from the group consisting of groups 4,        5, 6, 7, 8, 9, 10, 11 and 12 of the Periodic Table, for instance        a metal selected from the group consisting of ruthenium, osmium,        iron, molybdenum, tungsten, titanium, rhenium, technetium,        lanthanum, copper, chromium, manganese, palladium, platinum,        rhodium, vanadium, zinc, cadmium, mercury, gold, silver, nickel        and cobalt;    -   said multi-coordinated metal complex (a) is a penta-coordinated        metal complex or a tetra-coordinated metal complex, for instance        wherein (1) said at least one multidentate Schiff base        ligand (i) is a bidentate ligand and said multi-coordinated        metal complex (a) comprises two other ligands (ii), or        wherein (2) said at least one multidentate Schiff base        ligand (i) is a tridentate ligand and said multi-coordinated        metal complex (a) comprises a single other ligand (ii);    -   said at least one multidentate Schiff base ligand (i) has one of        the general formulae (IA) and (IB) referred to in FIG. 1,        wherein:        -   Z is selected from the group consisting of oxygen, sulfur            and selenium;        -   R″ and R′″ are each a radical independently selected from            the group consisting of hydrogen, C₁₋₇ alkyl, C₃₋₁₀            cycloalkyl, C₁₋₆ alkyl-C₁₋₆ alkoxysilyl, C₁₋₆            alkyl-aryloxysilyl, C₁₋₆ alkyl-C₃₋₁₀ cycloalkoxysilyl, aryl            and heteroaryl, or R″ and R′″ together form an aryl or            heteroaryl radical, each said radical being optionally            substituted with one or more, preferably 1 to 3,            substituents R₅ each independently selected from the group            consisting of halogen atoms, C₁₋₆ alkyl, C₁₋₆ alkoxy, aryl,            alkylsulfonate, arylsulfonate, alkylphosphonate,            arylphosphonate, C₁₋₆ alkyl-C₁₋₆ alkoxysilyl, C₁₋₆            alkyl-aryloxysilyl, C₁₋₆ alkyl-C₃₋₁₀ cycloalkoxysilyl,            alkylammonium and arylammonium;        -   R′ is either as defined for R″ and R′″ when included in a            compound having the general formula (IA) or, when included            in a compound having the general formula (IB), is selected            from the group consisting of C₁₋₇ alkylene and C₃₋₁₀            cycloalkylene, the said alkylene or cycloalkylene group            being optionally substituted with one or more substituents            R₅;        -   at least one of said other ligands (ii) of said            multi-coordinated metal complex (a) is a derivative, wherein            one or more hydrogen atoms is substituted with a group            providing constraint steric hindrance, of a N-heterocyclic            carbene selected from the group consisting of            imidazol-2-ylidene, dihydroimidazol-2-ylidene,            oxazol-2-ylidene, triazol-5-ylidene, thiazol-2-ylidene,            bis(imidazolin-2-ylidene) bis(imidazo-lidin-2-ylidene),            pyrrolylidene, pyrazolylidene, dihydropyrrolylidene,            pyrrolylidinylidene and benzo-fused derivatives thereof, or            a non-ionic prophosphatrane superbase;        -   at least one of said other ligands (ii) of said            multi-coordinated metal complex (a) is an anionic ligand            selected from the group consisting of C₁₋₂₀ alkyl, C₁₋₂₀            alkenyl, C₁₋₂₀ alkynyl, C₁₋₂₀ carboxylate, C₁₋₂₀ alkoxy,            C₁₋₂₀ alkenyloxy, C₁₋₂₀ alkynyloxy, aryl, aryloxy, C₁₋₂₀            alkoxycarbonyl, C₁₋₈ alkylthio, C₁₋₂₀ alkylsulfonyl, C₁₋₂₀            alkylsulfinyl C₁₋₂₀ alkylsulfonate, arylsulfonate, C₁₋₂₀            alkylphosphonate, arylphosphonate, C₁₋₂₀ alkylammonium,            arylammonium, halogen, C₁₋₂₀ alkyldiketonate,            aryldiketonate, nitro and cyano;        -   at least one of said other ligands (ii) of said            multi-coordinated metal complex (a) is a carbene ligand            represented by the general formula=[C═]_(y)CR₃R₄, wherein:        -   y is an integer from 0 to 3 inclusive, and        -   R₃ and R₄ are each hydrogen or a hydrocarbon radical            selected from the group consisting of C₁₋₂₀ alkyl, C₁₋₂₀            alkenyl, C₁₋₂₀ alkynyl, C₁₋₂₀ carboxylate, C₁₋₂₀ alkoxy,            C₁₋₂₀ alkenyloxy, C₁₋₂₀ alkynyloxy, aryl, aryloxy, C₁₋₂₀            alkoxycarbonyl, C₁₋₈ alkylthio, C₁₋₂₀ alkylsulfonyl, C₁₋₂₀            alkylsulfinyl C₁₋₂₀ alkylsulfonate, arylsulfonate, C₁₋₂₀            alkylphosphonate, arylphosphonate, C₁₋₂₀ alkylammonium and            arylammonium; or R₃ and R₄ together may form a fused            aromatic ring system such as, but not limited to, one having            the formula (IVC) referred to in FIG. 4, i.e. such as a            phenylindenylidene ligand;        -   said at least one multidentate Schiff base ligand (i) is a            tetradentate ligand and said multi-coordinated metal            complex (a) comprises one or two other ligands (ii) being            non-anionic ligands L⁷ selected from the group consisting of            aromatic and unsaturated cycloaliphatic groups, preferably            aryl, heteroaryl and C₄₋₂₀ cycloalkenyl groups, wherein the            said aromatic or unsaturated cycloaliphatic group is            optionally substituted with one or more C₁₋₇ alkyl groups or            electron-withdrawing groups such as, but not limited to,            halogen, nitro, cyano, (thio)carboxylic acid,            (thio)carboxylic acid (thio)ester, (thio)carboxylic acid            (thio)amide, (thio)carboxylic acid anhydride and (thio)            carboxylic acid halide;

The present invention will now be described with respect to a fewpreferred embodiments of the multicoordinated metal complex (a) to bemodified by reaction with an activating metal or silicon compound (b),optionally in the presence of a further reactant (c) being an organicacid (such as defined hereinabove) or having the structural formula RYH.

A first species of a multicoordinated metal complex (a) suitable forreaction according to this invention with an activating metal or siliconcompound (b), optionally in the presence of a reactant (c) being anorganic acid or having the structural formula RYH, is a five-coordinatemetal complex, a salt, a solvate or an enantiomer thereof, such asdisclosed in WO 03/062253 i.e. comprising a carbene ligand, amultidentate ligand and one or more other ligands, wherein:

-   -   at least one of said other ligands (ii) is a constraint steric        hindrance ligand having a pKa of at least 15 (said pKa being        measured under standard conditions, i.e. at about 25° C. usually        in dimethylsulfoxide (DMSO) or in water depending upon the        solubility of the ligand),    -   the multidentate ligand is a multidentate Schiff base ligand        comprising an imino group and being coordinated to the metal, in        addition to the nitrogen atom of said imino group, through at        least one further heteroatom selected from the group consisting        of oxygen, sulfur and selenium, and    -   said other ligands (ii) are preferably unable of protonation by        hydrogen halide.

The five-coordinate metal complex of this first species may be either amonometallic complex or a bimetallic complex wherein one metal ispenta-coordinated and the other metal is tetra-coordinated with one ormore neutral ligands and one or more anionic ligands. In the lattercase, the two metals M and M′ may be the same or different. Specificexamples of such a bimetallic complexes are shown in the generalformulae (IVA) and (IVB) referred to in FIG. 4, wherein:

-   -   Z, R′, R″ and R″ are as previously defined with respect to        formulae (IA) and (IB),    -   M and M′ are each a metal independently selected from the group        consisting of ruthenium, osmium, iron, molybdenum, tungsten,        titanium, rhenium, technetium, lanthanum, copper, chromium,        manganese, palladium, platinum, rhodium, vanadium, zinc,        cadmium, mercury, gold, silver, nickel and cobalt;    -   y represents the number of sp₂ carbon atoms between M and the        carbon atom bearing R₃ and R₄ and is an integer from 0 to 3        inclusive;    -   R₃ and R₄ are each hydrogen or a radical selected from the group        consisting of C₁₋₂₀ alkyl, C₂₋₂₀ alkenyl, C₂₋₂₀ alkynyl, C₁₋₂₀        carboxylate, C₁₋₂₀ alkoxy, C₂₋₂₀ alkenyloxy, C₂₋₂₀ alkynyloxy,        aryl, aryloxy, C₁₋₂₀ alkoxycarbonyl, C₁₋₈ alkylthio, C₁₋₂₀        alkylsulfonyl, C₁₋₂₀ alkylsulfinyl C₁₋₂₀ alkylsulfonate,        arylsulfonate, C₁₋₂₀ alkylphosphonate, arylphosphonate, C₁₋₂₀        alkylammonium and arylammonium;    -   R′ and one of R₃ and R₄ may be bonded to each other to form a        bidentate ligand;    -   X₁, X₂ and X₃ are anionic ligands as defined below;    -   L is a neutral electron donor; and    -   R₃ and R₄ together may form a fused aromatic ring system, i.e. a        phenylindenylidene ligand,        including salts, solvates and enantiomers thereof.

The multidentate Schiff base ligand included in this first species (a)may be either:

-   -   a bidentate Schiff base ligand, in which case the        multicoordinated metal complex (a) comprises two other ligands,        or    -   a tridentate Schiff base ligand, in which case the        multicoordinated metal complex (a) comprises a single other        ligand.

Preferably the metal in a five-coordinate metal complex (a) of thisinvention is a transition metal selected from the group consisting ofgroups 4, 5, 6, 7, 8, 9, 10, 11 and 12 of the Periodic Table. Morepreferably the said metal is selected from the group consisting ofruthenium, osmium, iron, molybdenum, tungsten, titanium, rhenium,technetium, lanthanum, copper, chromium, manganese, palladium, platinum,rhodium, vanadium, zinc, cadmium, mercury, gold, silver, nickel andcobalt.

The carbene ligand in a five-coordinate metal complex (a) of thisinvention may be an alkylidene ligand, a benzylidene ligand, avinylidene ligand, an indenylidene ligand, a heteroatom-containingalkylidene ligand, a phenylindenylidene ligand, an allenylidene ligandor a cumulenylidene ligand, e.g. buta-1,2,3-trienylidene,penta-1,2,3,4-tetraenylidene and the like, i.e. from 1 to 3 sp₂ carbonatoms may be present between the metal M and the group-bearing carbonatom.

Methods for making five-coordinate metal complexes (a₁) according tothis first species of the invention are already extensively disclosed inWO 03/062253.

A second species of a multicoordinated metal complex (a₂) suitable forreaction according to this invention with an activating metal or siliconcompound (b) optionally in the presence of a reactant (c) being anorganic acid or having the general formula RYH is a four-coordinatemonometallic complex comprising a multidentate ligand and one or moreother ligands, wherein:

-   -   at least one of said other ligands (ii) is a constraint steric        hindrance ligand having a pKa of at least 15, or is a group        selected from aromatic and unsaturated cycloaliphatic,        preferably aryl and C₄₋₂₀ cycloalkenyl (such as cyclooctadienyl,        norbornadienyl, cyclopentadienyl and cyclooctatrienyl) groups,        the said group being optionally substituted with one or more        C₁₋₇ alkyl groups,    -   the multidentate ligand is a multidentate Schiff base ligand        comprising an imino group and being coordinated to the metal, in        addition to the nitrogen atom of said imino group, through at        least one further heteroatom selected from the group consisting        of oxygen, sulfur and selenium, and    -   said other ligands (ii) are preferably unable of protonation by        hydrogen halide. Alike in the first species, one of said other        ligands (ii) present in the four-coordinate monometallic complex        of this second species of the invention may be an anionic ligand        such as defined previously.

More specifically, the constraint steric hindrance ligand having a pKaof at least 15 that may be included in a multicoordinated metal complex(a) may be a derivative, wherein one or more hydrogen atoms issubstituted with a group providing constraint steric hindrance, of thefollowing groups:

-   -   imidazol-2-ylidene (pKa=24),    -   dihydroimidazol-2-ylidene (pKa higher than 24),    -   oxazol-2-ylidene,    -   triazol-5-ylidene,    -   thiazol-2-ylidene,    -   pyrrolylidene (pKa=17.5),    -   pyrazolylidene,    -   dihydropyrrolylidene,    -   pyrrolylidinylidene (pKa=44),    -   bis(imidazoline-2-ylidene) and bis(imidazolidine-2-ylidene),    -   benzo-fused derivatives such as indolylidene (pKa=16), and    -   non-ionic prophosphatrane superbases, namely as described in        U.S. Pat. No. 5,698,737, preferably        trimethyltriazaprophosphatrane P(CH₃NCH₂CH₂)₃N known as Verkade        superbase.

The constraint steric hindrance group being present in such ligand maybe for instance a branched or substituted group, e.g. a ter-butyl group,a substituted C₃₋₁₀ cycloalkyl group, an aryl group having two or moreC₁₋₇ alkyl substituents (such as 2,4,6-trimethylphenyl (mesityl),2,6-dimethylphenyl, 2,4,6-triisopropylphenyl or 2,6-diisopropylphenyl),or a heteroaryl group (such as pyridinyl) having two or more C₁₋₇ alkylsubstituents.

As previously indicated, the multidentate Schiff base ligand (i)included either in the five-coordinate metal complex of the firstspecies or in the four-coordinate monometallic complex of the secondspecies may have one of the general formulae (IA) and (1B) referred toin FIG. 1, with Z, R′, R″ and R′″ being as defined above. In thedefinition of the ligands having the general formula (IA), the group R′is preferably selected from methyl, phenyl and substituted phenyl (e.g.dimethylbromophenyl or diisopropylphenyl). In the definition of theligands having the general formula (IB), the group R′ is preferablymethylidene or benzylidene.

Methods for making four-coordinate monometallic complexes (a₂) accordingto this second species are already extensively disclosed in WO03/062253.

A third species of a multicoordinated metal complex (a₃) suitable forreaction according to this invention with an activating metal or siliconcompound (b), optionally in the presence of a reactant (c) being anorganic acid or having the general formula RYH, is an at leasttetra-coordinated metal complex, a salt, a solvate or an enantiomerthereof, comprising:

-   -   a multidentate Schiff base ligand (i) comprising an imino group        and being coordinated to the metal, in addition to the nitrogen        atom of said imino group, through at least one further        heteroatom selected from the group consisting of oxygen, sulfur        and selenium;    -   a non-anionic unsaturated ligand L¹ selected from the group        consisting of aromatic and unsaturated cycloaliphatic groups,        preferably aryl, heteroaryl and C₄₋₂₀ cycloalkenyl groups, the        said aromatic or unsaturated cycloaliphatic group being        optionally substituted with one or more C₁₋₇ alkyl groups or        with electron-withdrawing groups such as, but not limited to,        halogen, nitro, cyano, (thio)carboxylic acid, (thio)carboxylic        acid (thio)ester, (thio)carboxylic acid (thio)amide,        (thio)carboxylic acid anhydride and (thio) carboxylic acid        halide; and    -   a non-anionic ligand L² selected from the group consisting of        C₁₋₇ alkyl, C₃₋₁₀ cycloalkyl, aryl, arylalkyl, alkylaryl and        heterocyclic, the said group being optionally substituted with        one or more preferably electron-withdrawing substituents such        as, but not limited to, halogen, nitro, cyano, (thio)carboxylic        acid, (thio)carboxylic acid (thio)ester, (thio)carboxylic acid        (thio)amide, (thio)carboxylic acid anhydride and (thio)        carboxylic acid halide,        provided that said other ligands L¹ and L² are unable of        protonation by hydrogen halide.

In this third species (a₃), the multidentate ligand (i) is preferably aN,O-bidentate Schiff base ligand or N,S-bidentate Schiff base ligand,most preferably a bidentate Schiff base ligand as shown in formulae (IA)or (IB) in FIG. 1 and described in more detail hereinabove, in whichcase the metal complex is tetra-coordinated. The multidentate ligand (i)may also be a tridentate Schiff base, in which case the metal complex ispenta-coordinated.

The at least tetra-coordinated metal complex (a₃) according to thisthird species is preferably a monometallic complex. Preferably the metalis a transition metal selected from the group consisting of groups 4, 5,6, 7, 8, 9, 10, 11 and 12 of the Periodic Table. More preferably, saidmetal is selected from the group consisting of ruthenium, osmium, iron,molybdenum, tungsten, titanium, rhenium, technetium, lanthanum, copper,chromium, manganese, palladium, platinum, rhodium, vanadium, zinc,cadmium, mercury, gold, silver, nickel and cobalt.

Each of the metal, the ligand L¹ and the ligand L² may, independentlyfrom each other, be any of the above-mentioned metals or any of theabove-mentioned groups with any of the substituents listed for suchgroups, including any of the individual meanings for such groups orsubstituents which are listed in the definitions given hereinabove.Preferably the non-anionic ligand L² has constraint steric hindrancesuch as, but not limited to, tert-butyl, neopentyl and mono- orpolysubstituted phenyl, e.g. pentafluorophenyl. L² may also be a linearC₁₋₇ alkyl such as methyl, or an aryl such as phenyl. Preferably thenon-anionic unsaturated ligand L¹ also has constraint steric hindrance(such as, but not limited to, alkylaryl and alkylheteroaryl, e.g. xylyl,cumenyl or mesityl).

The at least tetra-coordinated metal complex (a₃) according to thisthird species may for instance, but without limitation, be madeaccording to the following procedure: a metal (e.g. thallium) salt ofthe multidentate ligand (e.g. the bidentate or tridentate Schiff base)is first reacted with a preferably bimetallic metal complex of thedesired metal, more preferably a homobimetallic complex wherein thedesired metal is coordinated with a non-anionic unsaturated ligand L¹and at least one anionic ligand, such as [RuCl₂(p-cymene)]₂,[RuCl₂(COD)]₂ or [RuCl₂(NBD)]₂, wherein COD and NBD respectively meancyclooctadiene and norbornadiene. After removal of the metal salt formedwith the anionic ligand, e.g. thallium chloride, the intermediatecomplex produced, i.e. a complex wherein the desired metal iscoordinated with a non-anionic unsaturated ligand L¹, the multidentateligand (e.g. the bidentate or tridentate Schiff base) and an anionicligand, is reacted with a combination of the non-anionic ligand L² andan alcali or alcaline-earth metal, e.g. a C₁₋₇ alkyllithium, a C₁₋₇alkylsodium, phenyllithium, or a Grignard reagent such asphenylmagnesium chloride, phenylmagnesium bromide orpentafluorophenylmagnesium chloride. Recovery of the desired at leasttetra-coordinated metal complex of the third embodiment of the inventionmay suitably be achieved by removal of the alcali or alcaline-earthmetal salt formed with the anionic ligand, followed by purificationusing conventional techniques. High yields of the pure at leasttetra-coordinated metal complex of this embodiment may thus be achievedin a simple two-steps method.

A fourth species of a multicoordinated metal complex (a₄) suitable forreaction according to this invention with an activating metal or siliconcompound (b), optionally in the presence of a reactant (c) being anorganic acid or having the general formula RYH, is a hexa-coordinatedmetal complex, a salt, a solvate or an enantiomer thereof, comprising:

-   -   a multidentate Schiff base ligand (i) comprising an imino group        and being coordinated to the metal, in addition to the nitrogen        atom of said imino group, through at least one further        heteroatom selected from the group consisting of oxygen, sulfur        and selenium;    -   at least one non-anionic bidentate ligand L³ being different        from the multidentate ligand; and    -   at most two anionic ligands L⁴,        provided that said ligands L³ and L⁴ are unable of protonation        by hydrogen halide.

Said hexa-coordinated metal complex (a) is preferably a bimetalliccomplex wherein each metal is hexa-coordinated. The two metals may bethe same or different. Preferably each metal is a transition metalselected from the group consisting of groups 4, 5, 6, 7, 8, 9, 10, 11and 12 of the Periodic Table. More preferably each said metal isindependently selected from the group consisting of ruthenium, osmium,iron, molybdenum, tungsten, titanium, rhenium, technetium, lanthanum,copper, chromium, manganese, palladium, platinum, rhodium, vanadium,zinc, cadmium, mercury, gold, silver, nickel and cobalt.

The multidentate ligand (i) is preferably defined as in the previousembodiments of the invention, i.e. preferably is a bidentate ortridentate Schiff base. The non-anionic bidentate ligand L³ ispreferably a polyunsaturated C₃₋₁₀ cycloalkenyl group such as, but notlimited to, norbornadiene, cyclooctadiene, cyclopentadiene,cyclohexadiene, cycloheptadiene or cycloheptatriene, or a heteroarylgroup such as defined hereinabove (preferably wherein the heteroatom isnot nitrogen, phosphorus, arsenic or antimony in order to avoid a riskof protonation by the acid used for modifying the metal complex), forinstance (but without limitation) a 1-hetero-2,4-cyclopentadiene such asfuran or thiophene, or a fused-ring derivative thereof such asbenzofuran, thienofuran or benzothiophene, or a six-memberedheteroaromatic compound such as pyran or a fused-ring derivative thereofsuch as cyclopentapyran, chromene or xanthene. Each anionic ligand L⁴ ispreferably selected from the group consisting of C₁₋₂₀ carboxylate,C₁₋₂₀ alkoxy, C₂₋₂₀ alkenyloxy, C₂₋₂₀ alkynyloxy, aryloxy, C₁₋₂₀alkoxycarbonyl, C₁₋₇ alkylthio, C₁₋₂₀ alkylsulfonyl, C₁₋₂₀ alkylsulfinylC₁₋₂₀ alkylsulfonate, arylsulfonate, C₁₋₂₀ alkylphosphonate,arylphosphonate, C₁₋₂₀ alkylammonium, arylammonium, alkyldiketonate(e.g. acetylacetonate), aryldiketonate, halogen, nitro and cyano, eachof the said groups being as defined above. When said hexa-coordinatedmetal complex is monometallic, it preferably has only one anionic ligandL⁴.

The hexa-coordinated metal complex (a₄) according to this fourth speciesmay for instance, but without limitation, be made in high yield andpurity in a one-step procedure, wherein a metal (e.g. thallium) salt ofthe multidentate ligand (e.g. the bidentate or tridentate Schiff base)is reacted with a preferably bimetallic metal complex of the desiredmetal, more preferably a homobimetallic complex wherein the desiredmetal is coordinated with a non-anionic bidentate ligand L³ and at leastone anionic ligand, such as [RuCl₂L³]₂, e.g. [RuCl₂(COD)]₂ or[RuCl₂(NBD)]₂, wherein COD and NBD respectively mean cyclooctadiene andnorbornadiene. After removal of the metal salt formed with the anionicligand, e.g. thallium chloride, the desired hexa-coordinated metalcomplex (a) may be purified using conventional techniques.

More specifically, both the at least tetra-coordinated metal complex(a₃) of the third species and the hexa-coordinated metal complex (a₄) ofthe fourth species may have, as a multidentate ligand (i), a bidentateSchiff base having one of the general formulae (IA) or (IB) referred toin FIG. 1, wherein Z, R′, R″ and R′″ are as previously defined. In thisspecific case, preferably R″ and R″ together form a phenyl group whichmay be substituted with one or more preferably branched alkyl groupssuch as isopropyl or tert-butyl. The class of bidentate Schiff baseshaving the general formula (IA) is well known in the art and may be madefor instance by condensing a salicylaldehyde with a suitably substitutedaniline. The class of bidentate Schiff bases having the general formula(IB) may be made for instance by condensing benzaldehyde with a suitablyselected amino-alcohol such as o-hydroxyaniline (when Z is oxygen), anamino-thiol (when Z is sulfur).

A fifth embodiment of a multicoordinated metal complex (a₅) suitable forreaction according to this invention with an activating metal or siliconcompound (b), optionally in the presence of a reactant (c) being anorganic acid or having the general formula RYH, is an at leastpenta-coordinated metal complex, a salt, a solvate or an enantiomerthereof, comprising:

-   -   a tetradentate ligand (i) comprising two Schiff bases, wherein        the nitrogen atoms of said two Schiff bases are linked with each        other through a C₁₋₇ alkylene or arylene linking group A; and    -   one or more non-anionic ligands L⁷ selected from the group        consisting of aromatic and unsaturated cycloaliphatic groups,        preferably aryl, heteroaryl and C₄₋₂₀ cycloalkenyl groups,        wherein the said aromatic or unsaturated cycloaliphatic group is        optionally substituted with one or more C₁₋₇ alkyl groups or        electron-withdrawing groups such as, but not limited to,        halogen, nitro, cyano, (thio)carboxylic acid, (thio)carboxylic        acid (thio)ester, (thio)carboxylic acid (thio)amide,        (thio)carboxylic acid anhydride and (thio) carboxylic acid        halide.

Each of the ligand L⁷ and the substituting groups may, independentlyfrom each other, be any of the above-mentioned groups, including any ofthe individual meanings for such groups or substituents which are listedin the definitions given hereinabove. Preferably the non-anionic ligandL⁷ has constraint steric hindrance such as, but not limited to, mono- orpolysubstituted phenyl, e.g. xylyl, cumenyl, cymenyl or mesityl.

The at least penta-coordinated metal complex (a₅) according to thisfifth species preferably is a monometallic complex. Preferably the metalis a transition metal selected from the group consisting of groups 4, 5,6, 7, 8, 9, 10, 11 and 12 of the Periodic Table. More preferably thesaid metal is selected from the group consisting of ruthenium, osmium,iron, molybdenum, tungsten, titanium, rhenium, technetium, lanthanum,copper, chromium, manganese, palladium, platinum, rhodium, vanadium,zinc, cadmium, mercury, gold, silver, nickel and cobalt.

More specifically, in such at least penta-coordinated metal complexes(a₅) of the fifth species, each said non-anionic ligand L⁷ may becymene, and the C₁₋₇ alkylene or arylene linking group A may besubstituted with one or more substituents preferably selected from thegroup consisting of chloro, bromo, trifluoromethyl and nitro. Preferablythe C₁₋₇ alkylene or arylene linking group A, together with the twolinked nitrogen atoms, is derived from o-phenylenediamine,ethylenediamine, 1,3-diaminopropane, 1,4-diaminobutane,1,5-diaminopentane, 1,6-diaminohexane or 1,7-diaminoheptane. Alsopreferably, each Schiff base of the tetradentate ligand (i) is derivedfrom salicylaldehyde or acetylacetone, wherein the salicylidene oracetylidene group included in each such Schiff base may be substitutedwith one or more substituents preferably selected from the groupconsisting of chloro, bromo, trifluoromethyl and nitro.

Suitable but non limiting examples of tetradentate ligands (i) withinthe scope of this fifth species have one of the general formulae (IIA)and (IIB) shown in FIG. 2. More specific examples include the so-calledsalen (i.e. bis(salicylaldehyde) ethylenediamine), saloph (i.e.bis(salicylaldehyde)o-phenylenediamine), hydroxy-acetoph, and accac(i.e. bis(acetylacetone) ethylenediamine) ligands, and substitutedderivatives thereof. In formulae (IIA) and (IIB), substituents X arepreferably selected from the group consisting of chloro, bromo,trifluoromethyl and nitro. In formula (IIA) substituents Y arepreferably selected from the group consisting of hydrogen and methyl. Apreferred tetradentate ligand isN,N′-bis(5-nitro-salicylidene)-ethylenediamine. Other suitable ligandsinclude N,N′-1,2-cyclohexylenebis(2-hydroxyacetophenonylideneimine),1,2-diphenylethylene-bis (2-hydroxyacetophenonylideneimine) and1,1′-binaphtalene-2,2′-diaminobis(2-hydroxyacetophenonylideneimine), allbeing described in Molecules (2002) 7:511-516.

The at least penta-coordinated metal complex (a₅) according to thisfifth species may be made by reacting a suitable tetradentate ligand (i)such as defined hereinabove with a preferably bimetallic complex of thedesired metal, more preferably a homobimetallic complex wherein thedesired metal is coordinated with a non-anionic ligand L⁷ and at leastone anionic ligand, such as [RuCl₂(p-cymene)]₂, [RuCl₂(COD)]₂ or[RuCl₂(NBD)]₂, wherein COD and NBD respectively mean cyclooctadiene andnorbornadiene.

When the reaction product of this invention is produced by modifying amulti-coordinated metal complex (a) with an activating metal or siliconcompound (b) in the presence of a further reactant (c) being an organicacid or having the general formula RYH, the molar ratio between, on theone hand, the hydrogen halide resulting from the reaction of (b) and (c)and, on the other hand, said multicoordinated metal complex (a) is animportant parameter in the practice of the invention. Contrary to theteaching of the prior art (U.S. Pat. No. 6,284,852), this ratio is notselected to perform ligand protonation (especially since anotherpreferred feature of this invention is the absence of protonatableligands in the multicoordinated metal complex), but is selected toachieve at least partial cleavage of a bond between the metal center ofthe multicoordinated metal complex (a) and at least one multidentateSchiff base ligand (i) of multicoordinated metal complex (a). Thereforeit was found desirable to select high values for the said molar ratio,said high values resulting both from a molar ratio above 5:1 between theactivating metal or silicon compound (b) and multicoordinated metalcomplex (a), and from a molar equivalent amount between the furtherreactant (c) being an organic acid or having the general formula RYH andsaid activating metal or silicon compound (b). Said molar ratio may beachieved step by step by progressively adding the reactant (c) to themulticoordinated metal complex (a) and the activating metal or siliconcompound (b), optionally in the presence of a solvent system aspreviously mentioned, over the predetermined contact time. The additionrate of the reactant may be changed, depending upon the multidentateSchiff base ligand (i) and the selected temperature, according toroutine experimentation.

The progress of reaction with the multicoordinated metal complex (a) maybe followed by one or more standard analytical techniques such as butnot limited to infrared spectroscopy, carbon nuclear magnetic resonance(NMR) and proton NMR. These techniques will also be helpful in thedetermination of the precise nature of the reaction product of theinvention. This nature may also be confirmed, after separation of thereaction product from the reaction medium and after its purification bysuitable techniques (such as but not limited to re-crystallisation), byobtaining an X-ray diffractogram of the reaction product crystallinepowder. Careful examination shows that the reaction product of theinvention comprises the product of at least partial cleavage of a bondbetween the metal center and a multidentate Schiff base ligand (i). Thebond that is partially cleaved as a result of the reaction may be acovalent bond or a coordination bond; it may be the bond between themetal center and the nitrogen atom of the Schiff base imino group, or itmay be the bond between the metal center and the heteroatom (oxygen,sulfur or selenium) of the Schiff base ligand, or both such bonds may besimultaneously at least partially cleaved. The present invention doesnot require the said cleavage to be complete, thus partial bond cleavageleading to a mixture of the starting multicoordinated metal complex andof one or more reaction products is also within the scope of theinvention. Because, as disclosed hereinafter, the modification reactionof the invention may be performed in situ in the presence of organicmolecules or monomers such as unsaturated compounds (e.g. olefins,diolefins or alkynes) to be processed by the catalytic activity of theresulting reaction product, it is not essential that said reactionproduct may be isolated in the form of one single pure chemical entity.

In yet another aspect, the present invention also provides a supportedcatalyst, preferably for use in a heterogeneous catalytic reaction,comprising:

(A) a catalytic system comprising a catalytically active reactionproduct of:

-   -   (a) a multi-coordinated metal complex, a salt, a solvate or an        enantiomer thereof, said multi-coordinated metal complex        comprising (i) at least one multidentate Schiff base ligand        comprising an imino group and being coordinated to the metal, in        addition to the nitrogen atom of said imino group, through at        least one further heteroatom selected from the group consisting        of oxygen, sulfur and selenium, and (ii) one or more other        ligands, and    -   (b) an activating metal or silicon compound selected from the        group consisting of:        -   copper (I) halides,        -   zinc compounds represented by the formula Z_(n)(R₅)₂,            wherein R₅ is halogen, C₁₋₇ alkyl or aryl,        -   aluminum compounds represented by the formula AlR₆R₇R₈            wherein each of R₆, R₇ and R₈ is independently selected from            the group consisting of halogen and C₁₋₇ alkyl,        -   tin compounds represented by the formula SnR₉R₁₀R₁₁R₁₂            wherein each of R₉, R₁₀, R₁₁ and R₁₂ is independently            selected from the group consisting of halogen, C₁₋₂₀ alkyl,            C₃₋₁₀ cycloalkyl, aryl, benzyl and C₂₋₇ alkenyl, and        -   silicon compounds represented by the formula SiR₁₃R₁₄R₁₅R₁₆            wherein each of R₁₃, R₁₄, R₁₅ and R₁₆ is independently            selected from the group consisting of hydrogen, halogen,            C₁₋₂₀ alkyl, halo C₁₋₇ alkyl, aryl, heteroaryl and vinyl,            and    -   (c) optionally a further reactant being an organic acid (such as        defined hereinabove) or having the formula RYH, wherein Y is        selected from the group consisting of oxygen, sulfur and        selenium, and R is selected from the group consisting of        hydrogen, aryl, heteocyclic, heterocyclic-substituted alkyl,        arylalkyl and C₁₋₇ alkyl, and        (B) a supporting amount of a carrier suitable for supporting        said catalytic system (a).

The catalytic system (A) included in the supported catalyst of thisaspect of the invention may, in addition to the above-described reactionproduct, comprise one or more other catalytic species being known to theskilled person to exhibit catalytic activity in the reaction, forinstance the metathesis reaction of an unsaturated compound, to bepromoted. Such optional one or more other catalytic species should notbe capable of negatively interfering with the components of the reactionproduct of the invention during the formation of said reaction product.For instance they should not be capable of desactivating the metal orsilicon compound (b) and/or the optional further reactant (c).

In such a supported catalyst, said carrier (B) may be selected from thegroup consisting of porous inorganic solids (including silica, zirconiaand alumino-silica), such as amorphous or paracrystalline materials,crystalline molecular sieves and modified layered materials includingone or more inorganic oxides, and organic polymer resins such aspolystyrene resins and derivatives thereof.

Porous inorganic solids that may be used as carriers (B) for thesupported catalysts of the invention preferably have an openmicrostructure that allows molecules access to the relatively largesurface areas of these materials, thereby enhancing their catalyticand/or sorptive activity. These porous materials can be sorted intothree broad categories using the details of their microstructure as abasis for classification. These categories are the amorphous andparacrystalline supports, the crystalline molecular sieves and modifiedlayered materials. The detailed differences in the microstructures ofthese materials manifest themselves in the catalytic and/or sorptivebehavior of the materials, as well as in differences in variousobservable properties used to characterize them, such as their surfacearea, pore sizes, and pore size distribution, the presence or absence ofX-ray diffraction patterns and the details in such patterns, and theappearance of the material microstructure when observed by transmissionelectron microscopy and/or electron diffraction methods. Amorphous andparacrystalline materials represent an important class of porousinorganic solids that have been used for many years in industrialapplications. Typical examples of these materials are the amorphoussilicas commonly used in catalyst formulations and the paracrystallinetransitional aluminas used as solid acid catalysts and petroleumreforming catalyst supports. The term “amorphous” is used here toindicate a material with no long range order and can be somewhatmisleading, since almost all materials are ordered to some degree, atleast on the local scale. An alternate term that has been used todescribe these materials is “X-ray indifferent”. The microstructure ofthe silicas consists of 100-250 Angstrom particles of dense amorphoussilica (Kirk-Othmer Encyclopedia of Chemical Technology, 3rd. ed., vol.20, 766-781 (1982)), with the porosity resulting from voids between theparticles.

Paracrystalline materials such as the transitional aluminas also have awide distribution of pore sizes, but better defined X-ray diffractionpatterns usually consisting of a few broad peaks. The microstructure ofthese materials consists of tiny crystalline regions of condensedalumina phases and the porosity of the materials results from irregularvoids between these regions (K. Wefers and Chanakya Misra, “Oxides andHydroxides of Aluminum”, Technical Paper No 19 Revised, Alcoa ResearchLaboratories, 54-59 (1987)). Since, in the case of either material,there is no long range order controlling the sizes of pores in thematerial, the variability in pore size is typically quite high. Thesizes of pores in these materials fall into a regime called themesoporous range, including (for example) pores within the range ofabout 1.5 to about 20 nm.

In sharp contrast to these structurally ill-defined solids, there arematerials whose very narrow pore size distribution is controlled by theprecisely repeating crystalline nature of the material's microstructure.These materials are usually called “molecular sieves”, the mostimportant examples of which are zeolites. Zeolites, both natural andsynthetic, have been demonstrated in the past to have catalyticproperties for various types of hydrocarbon conversion. Certain zeoliticmaterials are ordered, porous crystalline aluminosilicates having adefinite crystalline structure as determined by X-ray diffraction,within which there are a large number of smaller cavities which may beinterconnected by a number of still smaller channels or pores. Thesecavities and pores are uniform in size within a specific zeoliticmaterial. Since their pore dimensions are such as to accept foradsorption molecules of certain dimensions while rejecting those oflarger dimensions, these materials are known as “molecular sieves” andare used in various ways to take advantage of this property. Suchmolecular sieves, both natural and synthetic, include a wide variety ofpositive ion-containing crystalline silicates. These silicates can bedescribed as a rigid three-dimensional framework of SiO₄ and a PeriodicTable Group IIIB element oxide, e.g., AlO₄, in which the tetrahedra arecrosslinked by the sharing of oxygen atoms whereby the ratio of thetotal Group IIIB element, e.g., aluminum, and Group IVB element, e.g.,silicon, atoms to oxygen atoms is 1:2. The electrovalence of thetetrahedra containing the Group IIIB element, e.g., aluminum, isbalanced by the inclusion in the crystal of a cation, for example, analkali metal or an alkaline earth metal cation. This can be expressedwherein the ratio of the Group IIIB element, e.g., aluminum, to thenumber of various cations, such as Ca, Sr, Na, K or Li, is equal to 1.One type of cation may be exchanged either entirely or partially withanother type of cation by using ion exchange techniques in aconventional manner. By means of such cation exchange, it has beenpossible to modify the properties of a given silicate by suitableselection of the cation. Many of these zeolites have come to bedesignated by letter or other convenient symbols, as illustrated byzeolites A (U.S. Pat. No. 2,882,243); X (U.S. Pat. No. 2,882,244); Y(U.S. Pat. No. 3,130,007); ZK-5 (U.S. Pat. No. 3,247,195); ZK-4 (U.S.Pat. No. 3,314,752); ZSM-5 (U.S. Pat. No. 3,702,886); ZSM-11 (U.S. Pat.No. 3,709,979); ZSM-12 (U.S. Pat. No. 3,832,449), ZSM-20 (U.S. Pat. No.3,972,983); ZSM-35 (U.S. Pat. No. 4,016,245); ZSM-23 (U.S. Pat. No.4,076,842); MCM-22 (U.S. Pat. No. 4,954,325); MCM-35 (U.S. Pat. No.4,981,663); MCM-49 (U.S. Pat. No. 5,236,575); and PSH-3 (U.S. Pat. No.4,439,409). The latter refers to a crystalline molecular sievecomposition of matter made from a reaction mixture containinghexamethyleneimine, an organic compound which acts as directing agentfor synthesis of a layered MCM-56. A similar composition, but withadditional structural components, has been disclosed in EP-A-293,032.Hexamethyleneimine is also taught for making the crystalline molecularsieves MCM-22, MCM-35, MCM-49, and ZSM-12 (U.S. Pat. No. 5,021,141). Amolecular sieve composition SSZ-25 is taught in U.S. Pat. No. 4,826,667and EP-A-231,860, said zeolite being synthesized from a reaction mixturecontaining an adamantane quaternary ammonium ion. Molecular sievematerial being selected from the group consisting of zeolites REY, USY,REUSY, dealuminated Y, ultrahydrophobic Y, silicon-enriched dealuminatedY, ZSM-20, Beta, L, silicoaluminophosphates SAPO-5, SAPO-37, SAPO-40 andMCM-9, metalloalumino-phosphate MAPO-36, aluminophosphate VPI-5 andmesoporous crystalline MCM-41 are also suitable for including as acarrier (B) into a supported catalyst of this invention.

Certain layered materials, which contain layers capable of being spacedapart with a swelling agent, may be pillared to provide materials havinga large degree of porosity. Examples of such layered materials includeclays. Such clays may be swollen with water, whereby the layers of theclay are spaced apart by water molecules. Other layered materials arenot swellable with water, but may be swollen with certain organicswelling agents such as amines and quaternary ammonium compounds.Examples of such non-water swellable layered materials are described inU.S. Pat. No. 4,859,648 and include layered silicates, magadiite,kenyaite, trititanates and perovskites. Another example of a non-waterswellable layered material, which can be swollen with certain organicswelling agents, is a vacancy-containing titanometallate material, asdescribed in U.S. Pat. No. 4,831,006. Once a layered material isswollen, the material may be pillared by interposing a thermally stablesubstance, such as silica, between the spaced apart layers. Theaforementioned U.S. Pat. Nos. 4,831,006 and 4,859,648 describe methodsfor pillaring the non-water swellable layered materials describedtherein and are incorporated herein by reference for definition ofpillaring and pillared materials. Other patents teaching pillaring oflayered materials and the pillared products include U.S. Pat. Nos.4,216,188; 4,248,739; 4,176,090; and 4,367,163; and European PatentApplication 205,711. The X-ray diffraction patterns of pillared layeredmaterials can vary considerably, depending on the degree that swellingand pillaring disrupt the otherwise usually well-ordered layeredmicrostructure. The regularity of the microstructure in some pillaredlayered materials is so badly disrupted that only one peak in the lowangle region on the X-ray diffraction pattern is observed, at ad-spacing corresponding to the interlayer repeat in the pillaredmaterial. Less disrupted materials may show several peaks in this regionthat are generally orders of this fundamental repeat. X-ray reflectionsfrom the crystalline structure of the layers are also sometimesobserved. The pore size distribution in these pillared layered materialsis narrower than those in amorphous and paracrystalline materials butbroader than that in crystalline framework materials.

In yet another aspect, the present invention provides a method ofperforming a metathesis reaction of an unsaturated compound in thepresence of a catalytic component, wherein said catalytic componentcomprises a catalytically active reaction product of:

-   -   (a) a multi-coordinated metal complex, a salt, a solvate or an        enantiomer thereof, said multi-coordinated metal complex        comprising (i) at least one multidentate Schiff base ligand        comprising an imino group and being coordinated to the metal, in        addition to the nitrogen atom of said imino group, through at        least one further heteroatom selected from the group consisting        of oxygen, sulfur and selenium, and (ii) one or more other        ligands, and    -   (b) an activating metal or silicon compound selected from the        group consisting of copper (I) halides; zinc compounds        represented by the formula Zn(R₅)₂, wherein R₅ is halogen, C₁₋₇        alkyl or aryl; aluminum compounds represented by the formula        AlR₆R₇R₈ wherein each of R₆, R₇ and R₈ is independently selected        from the group consisting of halogen and C₁₋₇ alkyl; tin        compounds represented by the formula SnR₃R₁₀R₁₁R₁₂ wherein each        of R₉, R₁₀, R₁₁ and R₁₂ is independently selected from the group        consisting of halogen, C₁₋₂₀ alkyl, C₃₋₁₀ cycloalkyl, aryl,        benzyl and C₂₋₇ alkenyl; and silicon compounds represented by        the formula SiR₁₃R₁₄R₁₅R₁₆ wherein each of R₁₃, R₁₄, R₁₅ and R₁₆        is independently selected from the group consisting of hydrogen,        halogen, C₁₋₂₀ alkyl, halo C₁₋₇ alkyl, aryl, heteroaryl and        vinyl, and    -   (c) optionally a further reactant being an organic acid (as        defined hereinabove) or having the formula RYH, wherein Y is        selected from the group consisting of oxygen, sulfur and        selenium, and R is selected from the group consisting of        hydrogen, aryl, heterocyclic, heterocyclic-substituted alkyl,        arylalkyl and C₁₋₇ alkyl.

The metathesis reaction of an unsaturated compound according to thisaspect of the invention may be olefin metathesis (the latter being asexplained in the background of the invention or as defined inhttp://www.ilpi.com/organomet/olmetathesis.html), in particular thering-opening metathesis polymerisation of cyclic olefins, or acetylenicmetathesis (the latter being as defined inhttp://www.ilpi.com/organomet/acmetathesis.html, a reaction in which allcarbon-carbon triple bonds in a mixture of alkynes are cut and thenrearranged in a statistical fashion, and involving ametalla-cyclobutadiene intermediate).

The metathesis reaction of an unsaturated compound according to thisaspect of the invention may be conducted in a continuous,semi-continuous, or batch manner and may involve a liquid and/or gasrecycling operation as desired. The manner or order of addition of thereactants, catalyst, and solvent are usually not critical, but a fewpreferred embodiments will be described hereinafter. In particular, themetathesis reaction may be carried out in a liquid reaction medium thatcontains a solvent for the active catalyst, preferably one in which thereactants, including catalyst, are substantially soluble at the reactiontemperature.

In a first embodiment of this aspect of the invention, the metathesisreaction is an olefin metathesis reaction for transforming a firstolefin into at least one second olefin or into a linear olefin oligomeror polymer or into a cyclo-olefin. The invention thus relates to amethod for performing an olefin metathesis reaction comprisingcontacting at least one first olefin with the catalytic component,optionally supported on a suitable carrier such as described hereinabovewith reference to one previous aspect of the invention. The highactivity of the metal complexes of this invention cause these compoundsto coordinate with, and catalyze metathesis reactions between, manytypes of olefins. Exemplary olefin metathesis reactions enabled by themetal complexes of the present invention include, but are not limitedto, RCM of acyclic dienes, cross metathesis reactions, de-polymerizationof olefinic polymers and, more preferably, ROMP of strained cyclicolefins. In particular, the catalytic components of this invention maycatalyze ROMP of unsubstituted, monosubstituted and disubstitutedstrained mono-, bi- and polycyclic olefins with a ring size of at least3, preferably 3 to 5, atoms; examples thereof include norbornene,cyclobutene, norbornadiene, cyclopentene, dicyclopentadiene,cycloheptene, cyclooctene, 7-oxanorbornene, 7-oxanorbornadiene,cyclooctadiene, cyclododecene, mono- and disubstituted derivativesthereof, especially derivatives wherein the substituent may be C₁₋₇alkyl, cyano, diphenylphosphine, trimethylsilyl, methylaminomethyl,carboxylic acid or ester, trifluoromethyl, maleic ester, maleimido andthe like, such as disclosed in U.S. Pat. No. 6,235,856, the content ofwhich is incorporated herein in its entirety. The invention alsocontemplates ROMP of mixtures of two or more such monomers in anyproportions. Further examples include water-soluble cyclic olefins suchasexo-N—(N′,N′,N′-trimethylammonio)ethyl-bicyclo[2.2.1]hept-5-ene-2,3-dicarboximidechloride orexo-N—(N′,N′,N′-trimethylammonio)ethyl-bicyclo-7-oxabicyclo[2.2.1]hept-5-ene-2,3-dicarboximidechloride. As is well known to the skilled person, olefins such ascyclohexenes which have little or no ring strain cannot be polymerizedbecause there is no thermodynamic preference for polymer versus monomer.

A ROMP reaction according to the invention may be carried out in aninert atmosphere for instance by dissolving a catalytic amount of thecatalytic component in a suitable solvent and then adding one or more ofthe said strained cyclic olefins, optionally dissolved in the same oranother solvent, to the catalyst solution, preferably under agitation.Because a ROMP system is typically a living polymerisation process, twoor more different strained cyclic olefins may be polymerised insubsequent steps for making diblock and triblock copolymers, thuspermitting to tailor the properties of the resulting material, providedthat the ratio of chain initiation and chain propagation is suitablyselected. Solvents that may be used for performing ROMP include allkinds of organic solvents such as protic solvents, polar aproticsolvents and non-polar solvents, as well as supercritical solvents suchas carbon dioxide (while performing ROMP under supercriticalconditions), which are inert with respect to the strained cyclic olefinand the catalytic component under the polymerization conditions used.More specific examples of suitable organic solvents include, but are notlimited to, ethers (e.g. dibutyl ether, tetrahydrofuran, dioxane,ethylene glycol monomethyl or dimethyl ether, ethylene glycol monoethylor diethyl ether, diethylene glycol diethyl ether or triethylene glycoldimethyl ether), halogenated hydrocarbons (e.g. methylene chloride,chloroform, 1,2-dichloroethane, 1,1,1-trichloroethane or1,1,2,2-tetrachloroethane), carboxylic acid esters and lactones (e.g.ethyl acetate, methyl propionate, ethyl benzoate, 2-methoxyethylacetate, y-butyrolactone, δ-valerolactone or pivalolactone), carboxylicacid amides and lactams (e.g. N,N-dimethylformamide,N,N-diethylformamide, N,N-dimethylacetamide, tetramethylurea,hexamethyl-phosphoric acid triamide, γ-butyrolactam, ε-caprolactam,N-methyl-pyrrolidone, N-acetylpyrrolidone or N-methylcaprolactam),sulfoxides (e.g. dimethyl sulfoxide), sulfones (e.g. dimethyl sulfone,diethyl sulfone, trimethylene sulfone or tetramethylene sulfone),aliphatic and aromatic hydrocarbons (e.g. petroleum ether, pentane,hexane, cyclohexane, methylcyclohexane, benzene, chlorobenzene,o-dichlorobenzene, 1,2,4-trichlorobenzene, nitrobenzene, toluene orxylene), and nitriles (e.g. acetonitrile, propionitrile, benzonitrile orphenylacetonitrile).

The solubility of the polymer formed by ROMP will depend upon the choiceof the strained cyclic olefin, the choice of the solvent and themolecular weight and concentration of the polymer obtained. When thestrained cyclic olefin is polyunsaturated (e.g. dicyclopentadiene ornorbornadiene), the polymer obtained may often be insoluble, whateverthe solvent used. Polymerisation temperatures may range from about 0° C.to about 120° C., preferably 20° C. to 85° C., also depending upon thestrained cyclic olefin and the solvent. The duration of polymerisationmay be at least about 30 seconds, preferably at least about 1 minute,more preferably at least about 4 minutes, for instance about 30 minutes;the duration of polymerisation may be at most about 24 hours (althoughlonger times may be used at the expense of economic conditions),preferably at most about 4 hours, and more preferably at most about 2hours. The molar ratio of the strained cyclic olefin to the metal of thecatalytic component of the invention is not critical and, depending uponthe strained cyclic olefin to be polymerised, the selected temperatureand the selected duration of polymerisation, may be at least about 100,preferably at least 250, more preferably at least 500. The said molarratio is usually, i.e. for most strained cyclic olefins, at most about5,000,000, preferably at most 500,000 and more preferably at most200,000 in order to achieve optimal conversion within the aboverecommended duration of polymerisation. Before the polymer formedsolidifies in the reactor or mold or, at will, when a desired molecularweight of the polymer has been achieved (as may be controlled forinstance by monitoring reactor temperature and/or reaction mixtureviscosity), an oxidation inhibitor and/or a terminating orchain-transfer agent may be added to the reaction mixture, if needed.The choice of the terminating or chain-transfer agent used is notcritical to this invention, provided that the said terminating agentreacts with the catalytic component and produces another species whichis inactive, i.e. not able to further propagate the polymerisationreaction, under the prevailing conditions (e.g. temperature). Forinstance, adding a molar excess (with respect to the catalyticcomponent) of a carbonyl compound to the reaction mixture is able toproduced a metal oxo and an olefin (or polymer) capped with the formercarbonyl functionality; the cleaved polymer can then be separated fromthe catalyst by precipitation with methanol. Another way of cleaving thepolymer from the catalyst may be by the addition of a vinylalkylether.Alternatively, reaction with several equivalents of a chain-transferagent such as a diene is another way of cleaving the polymer chain,which method does not deactivate the catalytic component, permittingadditional monomer to be polymerised, however possibly at the risk ofbroadening molecular weight distribution.

Because the metal complexes of this invention are stable in the presenceof various functional groups, they may be used to catalyze metathesis ofa wide variety of olefins under a wide variety of process conditions. Inparticular the olefinic compound to be converted by a metathesisreaction may include one or more, preferably at most two, functionalatoms or groups, being for instance selected from the group consistingof ketone, aldehyde, ester (carboxylate), thioester, cyano, cyanato,epoxy, silyl, silyloxy, silanyl, siloxazanyl, boronato, boryl, stannyl,disulfide, carbonate, imine, carboxyl, amine, amide, carboxyl,isocyanate, thioisocyanate, carbodiimide, ether (preferably C₁₋₂₀ alkoxyor aryloxy), thioether (preferably C₁₋₂₀ thioalkoxy or thioaryloxy),nitro, nitroso, halogen (preferably chloro), ammonium, phosphonate,phosphoryl, phosphino, phosphanyl, C₁₋₂₀ alkylsulfanyl, arylsulfanyl,C₁₋₂₀ alkylsulfonyl, arylsulfonyl, C₁₋₂₀ alkylsulfinyl, arylsulfinyl,sulfonamido and sulfonate (preferably toluenesulfonate, methanesulfonateor trifluoro-methanesulfonate). The said olefin functional atom or groupmay be either part of a substituting group of the olefin or part of thecarbon chain of the olefin.

The metal complexes of this invention are also useful components forcatalyzing, at relatively low temperatures (from about 20° C. to 80°C.), in the presence or absence of a solvent, the ring-closingmetathesis of acyclic dienes such as, for instance, diallylic compounds(diallyl ether, diallyl thioether, diallyl phtalate, diallylaminocompounds such as diallylamine, diallylamino phosphonates, diallylglycine esters), 1,7-octadiene, substituted 1,6-heptadienes and thelike.

The metal complexes of this invention may also be used as catalyticcomponents for the preparation of telechelic polymers, i.e.macromolecules with one or more reactive end-groups which are usefulmaterials for chain extension processes, block copolymer synthesis,reaction injection moulding, and polymer network formation. An examplethereof is hydroxyl-telechelic polybutadiene which may be obtained from1,5-cycooctadiene, 1,4-diacetoxy-cis-2-butene and vinyl acetate. Formost applications, a highly functionalized polymer, i.e. a polymer withat least two functional groups per chain, is required. The reactionscheme for a telechelic polymer synthesis via ring opening metathesispolymerisation is well known to those skilled in the art: in such ascheme, acyclic olefins act as chain-transfer agents in order toregulate the molecular weight of the telechelic polymer produced. Whenα,ω-bifunctional olefins are used as chain-transfer agents, trulybi-functional telechelic polymers can be synthesized.

According to this aspect of the invention, olefin coupling may beperformed by cross-metathesis comprising the step of contacting a firstolefinic compound with the above-described catalytically active reactionproduct in the presence of a second olefin or functionalized olefin. Thesaid first olefinic compound may be a diolefin or a cyclic mono-olefinwith a ring size of at least 3 atoms, and the said metathesiscross-coupling is preferably performed under conditions suitable fortransforming said cyclic mono-olefin into a linear olefin oligomer orpolymer, or said diolefin into a mixture of a cyclic mono-olefin and analiphatic alpha-olefin.

Depending upon the selection of the starting substrates for the olefinmetathesis reaction and the desired organic molecule to be produced, theolefin metathesis reaction can yield a very wide range of end-productsincluding biologically active compounds. For instance the reaction maybe for transforming a mixture of two dissimilar olefins, at least one ofwhich is an alpha-olefin, selected from (i) cyclodienes containing from5 to 12 carbon atoms and (ii) olefins having the formula:

XHC═CH—(CH₂)_(r)—(CH═CH)_(a)—(CHX′)_(c)—(CH₂)_(t)—X″  (XIV),

into an unsaturated biologically active compound having the formula:

H(CH₂)_(z)—(CH═CH)_(a)—(CH₂)_(m)—(CH═CH)_(b)—(CH₂)_(p)X″  (XV), wherein

a is an integer from 0 to 2; b is selected from 1 and 2; c is selectedfrom 0 and 1; m and p are such that the hydrocarbon chain in formula (V)contains from 10 to 18 carbon atoms; r and t are such that the combinedtotal of carbon atoms in the hydrocarbon chains of the two dissimilarolefins of formula (XIV) is from 12 to 40; z is an integer from 1 to 10,and X, X′ and X″ are atoms or groups each independently selected fromhydrogen, halogen, methyl, acetyl, —CHO and —OR₁₂, wherein R₁₂ isselected from hydrogen and an alcohol protecting group selected from thegroup consisting of tetrahydropyranyl, tetrahydro-furanyl, Pert-butyl,trityl, ethoxyethyl and SiR₁₃R₁₄R₁₅ wherein R₁₃, R₁₄ and R₁₅ are eachindependently selected from C₁₋₇ alkyl groups and aryl groups.

The said unsaturated biologically active compound having the formula(XV) may be a pheromone or pheromone precursor, an insecticide or ainsecticide precursor, a pharmaceutically active compound or apharmaceutical intermediate, a fragrance or a fragrance precursor. A fewexamples of the said unsaturated biologically active compounds include,but are not limited to, 1-chloro-5-decene, 8,10-dodecadienol,dodecatrienol, 5-decenyl acetate, 11-tetradecenylacetate,1,5,9-tetradeca-triene and 7,11-hexadecadienyl acetate. The latter is apheronome commercially available under the trade name Gossyplure and isuseful in pest control by effectively disrupting the mating andreproductive cycles of specifically targeted insect species, and whichmay be produced from 1,5,9-tetradecatriene, the latter being obtainablefrom cyclooctadiene and 1-hexene according to the present invention.

Ring-opening metathesis polymerization (ROMP) reactions using thecatalytically active reaction product of the invention may proceed soquickly for olefinic monomers such as, but not limited to,dicyclopentadiene or oligomers thereof (i.e. Diels-Alder adducts formedwith about 1 to 20 cyclopentadiene units), or mixtures thereof withstrained monocyclic or polycyclic fused olefins (e.g. as defined in U.S.Pat. No. 6,235,856, the content of which is incorporated herein byreference), that polymerization control could become a problem in theabsence of appropriate measures. This kind of problem is likely to occurduring the molding of thermoset polymers wherein a liquid olefin monomerand a catalytic system are mixed and poured, cast or injected into amold and wherein on completion of polymerization (i.e. “curing” of thearticle) the molded part is removed from the mold before any post cureprocessing that may be required, such as in the Reaction InjectionMolding (hereinafter referred as “RIM”) technique. It is well known thatthe ability to control reaction rates, i.e. the pot life of the reactionmixture, becomes more important in the molding of larger parts usingthis technique. When using the catalytically active reaction products ofthis invention, extending the pot life of the reaction mixture and/orcontrolling the rate of olefin metathesis polymerisation reaction may beeffected in different ways, such as increasing the catalyst/olefin ratioand/or adding a polymerization retardant to the reaction mixture and/orselecting a particular mode of introduction of the olefin and thecomponents of the catalytically active reaction product into the reactor(e.g. the mold). For instance, when the catalytically active reactionproduct of the invention results from modification of themulticoordinated metal complex by an activating metal or siliconcompound alone (i.e. in the absence of a further reactant having thegeneral formula RYH), rate control of the polymerisation reaction can beachieved by an improved embodiment comprising:

-   -   (a) a first step of contacting the optionally supported        catalytic component of the invention with the olefin to be        polymerised by ring-opening metathesis polymerization in a        reactor at a first temperature at which said optionally        supported catalytic component is substantially unreactive        (inactive), and    -   (b) a second heat activation step of bringing the reactor        temperature (e.g. heating the contents of said reactor) up to a        second temperature above the said first temperature, at which        said optionally supported catalytic component is active, until        completion of polymerisation.

In a more specific version of this improved embodiment, heat activationoccurs in bursts rather than continuously, e.g. by repeating thesequence of steps (a) and (b).

Within the said controlled polymerization method, it should beunderstood that the non-reactivity of the catalytic component in thefirst step depends not only upon the first temperature but also upon thenature of the olefin(s) used in said molding process (e.g. RIMtechnique) and/or upon the olefin/catalytic component ratio. Preferablythe first temperature is about 20° C. but, for specific olefins orspecific olefin/catalytic component ratios, it may even be suitable tocool the reaction mixture below room temperature, e.g. down to about 0°C. The second temperature is preferably above 40° C. and may be up toabout 90° C.

Alternatively, when the catalytically active reaction product of theinvention results from modification of the multicoordinated metalcomplex by an activating metal or silicon compound in the presence of afurther reactant (such as an organic acid or having the general formulaRYH as described hereinabove), premature contact between said activatingmetal or silicon compound and said further reactant having the generalformula RYH may result in premature formation of hydrogen halide which,if gaseous (e.g. hydrogen iodide, hydrogen bromide or hydrogen chloriderespectively resulting from a metal or silicon compound including aniodine, bromine or chlorine atom), may escape from the reaction mixtureor at least result in unknown concentrations, rate control of themetathesis reaction can be achieved by an improved embodiment whereinthe unsaturated compound (e.g. olefin or alkyne) to be submitted tometathesis is distributed in at least two flows before introduction intothe reactor, said at least two flows comprising:

-   -   a first flow comprising a first portion of said unsaturated        compound in admixture with the multicoordinated metal complex        and the reactant having the general formula RYH, and optionally        a solvent, and    -   a second flow comprising a second portion of said unsaturated        compound in admixture with the activating metal or silicon        compound, and optionally a solvent.

According to this improved embodiment of the process, the activatingmetal or silicon compound and the further reactant being an organic acidor having the general formula RYH may be kept separated until entranceinto the reactor, thereby preventing premature formation of hydrogenhalide. Also, since the multicoordinated metal complex and the reactantbeing an organic acid or having the general formula RYH are usuallynon-reactive versus each other, this improved embodiment of the processensures that all amounts of the activating metal or silicon compound andof the further reactant being an organic acid or having the generalformula RYH are available for reaction and, consequently, that all insitu formed hydrogen halide is available for chemical modification ofthe multicoordinated metal complex. Within this improved embodiment ofthe process, each of the first flow and the second flow may additionallycomprise suitable additives and carriers, as long as such additives andcarriers do not interfere with the critical components of each flow,e.g. by desactivating the metal or silicon compound included in thesecond flow and/or the further reactant being an organic acid or havingthe general formula RYH included in the first flow. According to thisimproved embodiment of the process, the number of flows beforeintroduction into the reactor is not limited to two, for instance athird flow for a third portion of the unsaturated compound (e.g. olefinor alkyne) to be submitted to metathesis, optionally together with thefurther reactant being an organic acid or having the general formula RYHand optionally with a solvent but without the multicoordinated metalcomplex, may also be present. According to this improved embodiment ofthe process, the respective proportions of the first flow, the secondflow, and optionally the third flow, are not particularly restricted, aslong as the recommended molar ratios between the activating metal orsilicon compound, the further reactant being an organic acid or havingthe general formula RYH, the multicoordinated metal complex andunsaturated compound (e.g. olefin or alkyne) to be submitted tometathesis are met and, preferably, as long as the solubility of eachcomponent of the catalytic system into said unsaturated compound is alsomet.

ROMP using the catalytic components of this invention readily achievelinear or crosslinked polymers of the above-mentioned strained cyclicolefins, such as polynorbornenes and polydicyclopentadienes, with wellcontrolled characteristics, i.e. average molecular weight and molecularweight distribution (polydispersity).

Polymerisation, in particular when performed in a mold such as in theRIM technique, may also occur in the presence of one or more formulationauxiliaries, such as antistatics, antioxidants, ceramics, lightstabilizers, plasticizers, dyes, pigments, fillers, reinforcing fibers,lubricants, adhesion promoters, viscosity-enhancing agents and demoldingagents, all said auxilaries being well known in the art.

Depending upon the specific reaction involved in this aspect of thisinvention, and especially when the said reaction is ROMP of strainedcyclic olefins, reaction may also advantageously be performed undervisible light or ultra-violet light irradiation, e.g. using a source ofvisible light or ultra-violet light being able to deliver sufficientenergy to the reaction system.

The present invention will now be further explained by reference to thefollowing set of examples which should be understood as merelyillustrating various embodiments of the invention without limiting thescope thereof.

Examples 1-A to 1-E Preparation and Characterisation of Schiff BaseLigands

The following Schiff base ligands were prepared, purified andcharacterised as disclosed in WO 2005/035121:

-   -   N-(2,6-diisopropylphenyl)-2-hydroxy-3-tertbutyl-1-phenylmethaneimine        (Schiff base 1-A) represented by the structural formula:

-   -   N-(4-bromo-2,6-dimethyl)-2-hydroxy-3-tertbutyl-1-phenylmethaneimine        (Schiff base 1-B) represented by the structural formula:

-   -   N-(4-bromo-2,6-dimethylphenyl)-2-hydroxy-1-phenylmethaneimine        (Schiff base 1-C) represented by the structural formula:

-   -   N-(4-bromo-2,6-dimethylphenyl)-2-hydroxy-4-nitro-1-phenylmethaneimine        (Schiff to base 1-D) represented by the structural formula:

-   -   N-(2,6-diisopropylphenyl)-2-hydroxy-4-nitro-1-phenylmethaneimine        (Schiff base 1-E) represented by the structural formula:

Examples 2 to 8 Preparation and Characterisation of Schiff BaseSubstituted Ruthenium Complexes

The following ruthenium complexes coordinated with Schiff bases fromexamples 1-A to 1-E were prepared and characterised according to theprocedure described in examples 2-8 of WO 2005/035121:

-   -   example 2 (obtained from Schiff base 1-C and methyllithium)        represented by the structural formula:

-   -   example 3 (obtained from Schiff base 1-E and methyllithium)        represented by the structural formula:

-   -   example 4 (obtained from Schiff base 1-B and methyllithium)        represented by the structural formula:

-   -   example 5 (obtained from Schiff base 1-A and phenylmagnesium        chloride) represented by the structural formula:

-   -   example 6 (obtained from Schiff base 1-A in the second step)        represented by the structural formula:

-   -   example 7 (obtained from Schiff base 1-A and methyllithium)        represented by the structural formula:

-   -   example 8 (obtained from Schiff base 1-A and        pentafluorophenylmagnesium chloride) represented by the        structural formula:

Examples 9 and 10 Preparation and Characterisation of Bimetallic SchiffBase Substituted Ruthenium Complexes

The two following bimetallic Schiff base substituted ruthenium complexeswere made according to the procedure described in WO 2005/035121(examples 9-10):

-   -   example 9 represented by the structural formula:

-   -   example 10 represented by the structural formula:

Example 11 Manufacture of Multicoordinated Schiff Base RutheniumComplexes

This example illustrates an alternative route of manufacture for theSchiff base substituted ruthenium complexes represented by formulae(VII.a) to (VII.f) in example 6 and FIG. 1 of WO 03/062253 (i.e. havinga carbene ligand with a fused aromatic ring system having the formula(VI) shown in FIG. 3 of WO 03/062253). This alternative method isschematically shown in FIG. 5, wherein the following abbreviations areused:

Ph stands for phenyl,

-   -   Cy stands for cyclohexyl,    -   Me stands for methyl,    -   iPr stands for isopropyl, and    -   tBu stands for ter-butyl.

The scheme is self-understandable and shows a method which proceeds infive steps, starting from compound 34 and achieves, throughintermediates 35, 36, 37 and 66-68, the desired Schiff base substitutedruthenium complexes 69-71 with better yields than the method disclosedin examples 1-6 and FIG. 1 of WO 03/062253.

Example 12 Preparation and Characterisation of a Schiff-Base-SubstitutedRuthenium Complex

A Schiff base substituted ruthenium complex similar to the compound 70shown in FIG. 5 (i.e. with R₁=NO₂, R₂=methyl and R₃=bromo), with theonly exception that the carbene ligand with a fused aromatic ring systemis replaced with a=CHC₆H₅ carbene ligand, was manufactured according tothe procedure of example 11. This Schiff base substituted rutheniumcomplex may be represented by the general formula:

wherein ImesH₂ stands for dihydro-imidazol-2-ylidene and Ph stands forphenyl. This Schiff base substituted ruthenium complex was furthercharacterised by means of proton nuclear magnetic resonance (hereinafterreferred as NMR, performed at 300 MHz with C₆D₆ at 25° C.) and carbonNMR (performed at 75 MHz with C₆D₆) as follows:

¹H NMR (CDCl₃): δ 18.50 [1H, Ru═CHPh], 8.10 [d, 1H], 8.07 [d, 1H], 8.04[d, 1H], 7.58 [s, 2H], 7.42-7.38 [m, 1H], 7.05 [s, 2H], 7.02 [s, 2H],9.95 [s, 1H], 6.91 [s, 1H], 6.75 [s, 1H], 6.43 [1H], 6.36 [1H],4.12-4.01 [m, 2H, CH₂CH₂], 2.57 [s, 3H, CH₃], 2.40 [s, 3H, CH₃], 2.29[s, 3H, CH₃], 2.26 [s, 3H, CH₃], 2.13 [s, 3H, CH₃], 2.01 [s, 3H, CH₃],1.48 [s, 3H, CH₃] and 1.03 [s, 3H, CH₃]; and

¹³C NMR (CDCl₃): δ 301.77 [Ru═C], 219.27 [NCN], 174.70 [C═N], 167.39[C—O], 151.91, 150.13, 140.29-128.37, 123.99, 118.82, 118.03, 51.70[CH₂CH₂], 51.08 [CH₂CH₂], and 21.24-17.80.

Example 13 (Comparative) Ring Opening Polymerisation of Cyclooctadienewithout Activation of a Schiff Base Ruthenium Complex

Ring opening metathesis polymerisation of cyclooctadiene (beforehanddried over calcium hydride) was performed during 17 hours at 60° C. intetrahydrofuran (THF) as a solvent, while using the Schiff basesubstituted ruthenium complex of example 12 as a catalyst in a molarratio cyclooctadiene/catalyst equal to 500:1. A polymer having a numberaverage molecular weight of 59,000 and a polydispersity of 1.4 wasobtained in 96% yield.

Example 14 Ring Opening Polymerisation of Cyclooctadiene with Activationof a Schiff Base Ruthenium Complex

After charging an NMR-tube with the appropriate amount of the Schiffbase substituted ruthenium complex of example 12 as a catalyst dissolvedin deuterated toluene, there was added into the tube a mixture of:

-   -   cyclooctadiene (beforehand dried over calcium hydride) as the        monomer, and    -   a metal or silicon activator according to the invention.        The polymerization reaction was monitored as a function of time        at 20° C. by integrating olefinic ¹H signals of the formed        polymer and the disappearing monomer. Various activators        (aluminum trichloride being used as a solution in        tetrahydrofuran) and various catalyst/monomer/activator monomer        ratios were tested during various periods of time, and the        resulting monomer conversion was recorded in table 1.

TABLE 1 Time Conversion Entry Activator catalyst/monomer/activator(minutes) (%) 1 HSiCl₃ 1/30,000/70 30 93 60 100 2 HSiCl₃ 1/60,000/140 3070 60 100 3 HSiCl₃ 1/90,000/140 15 49 30 79 60 100 4 HSiCl₃1/120,000/210 30 68 60 100 5 HSiCl₃ 1/150,000/210 30 86 60 100 6 HSiCl₃1/300,000/300 30 78 60 85 900 100 7 HSiCl₃ 1/3,000,000/1000 30 47 8HSiCl₃ 1/90,000/140 30 89 60 100 9 HSiMe₂Cl 1/30,000/70 30 50 60 55 10SiMe₂Cl₂ 1/3,000/100 30 100 11 SiCl₄ 1/30,000/70 30 75 60 88 900 100 12SnCl₄ 1/3,000/100 120 31 13 CuCl 1/3,000/100 120 63 900 100

Example 15 (Comparative) Ring Closing Metathesis of DiethylDiallylmalonate without Activation of a Schiff Base Ruthenium Complex

An NMR-tube was charged with 0.6 mL of a catalyst solution in CD₂Cl₂(4.52 mM or 0.002712 mmole of the Schiff base substituted rutheniumcomplex of example 12 as a catalyst). Next 200 molar equivalents (0.13mL) of diethyl diallylmalonate was added and the NMR tube was closed.The progress of the ring closing reaction was monitored at 20° C. byintegration of ¹H signals of allylic protons of the reaction product andof the disappearing substrate. However no reaction product was obtainedafter 180 minutes under such conditions.

Example 16 Ring Closing Metathesis of Diethyl Diallylmalonate withActivation of a Schiff Base Ruthenium Complex

The procedure of example 15 was repeated, except that HSiCl₃ was dilutedinto diethyl diallylmalonate immediately prior to introduction into theNMR-tube, in such a way that the catalyst/substrate/HSiCl₃ ratio was1/200/50. Under such conditions, conversion of diethyl diallylmalonatewas 71% after 110 minutes, and 84% after 180 minutes.

Example 17 Ring Opening Polymerisation of Dicyclopentadiene withActivation of a Schiff Base Ruthenium Complex

This example illustrates an embodiment of a ROMP process with activationof the Schiff base substituted ruthenium complex obtained in example 12(acting as the catalyst to be activated) by both a chlorinated silane(CH₃Cl₂SiH) and a phenol (2,6-di-tert-butyl-4-sec-butylphenol,commercially available from Schenectady International, Inc., Korea underthe trade name ISONOX 132), wherein said silane activating compound andsaid phenol are kept separated until their entrance into thepolymerisation reactor.

The operating procedure was as follows: in a first 14 ml glass vessel, 1molar equivalent of the catalyst (dissolved in CH₂Cl₂) was mixed with 5ml dicyclopentadiene (hereinafter referred as DCPD), 60 molarequivalents ISONOX 132, and optionally 0.15 g of an additive. Saidadditive was either short glass fibres (2 mm length) in order toreinforce the resulting polymer (entry 4 in table 2) or an organicpigment (type: aromatic alcohol) commercially available under the tradename Disney Magic Artist from the company BIC (Clichy, France) in orderto impart color to the resulting polymer (entries 2-3 and 5 in table 2).The color of said pigment is specified in table 2 below for eachrelevant experiment. Another 14 ml glass vessel was filled with 5 mlDCPD, 22 μl vinylnorbornene (acting as a chain transfer agent) and 30molar equivalents CH₃Cl₂SiH (from a 10 mL solution of 800 μL CH₃Cl₂SiHin CH₂Cl₂). The content of the second vessel was added to the firstvessel and, at the moment of addition, time measurement was started. Thetotal volume of DCPD (10 ml) corresponds to 30,000 molar equivalents ofthe monomer with respect to the catalyst.

Reaction was allowed to proceed for a certain time (expressed in minutesin table 2 below), after which temperature quickly decreases. Thepolymerisation reaction was extremely exothermic, possibly involvingfoaming of the mixture, and the maximum temperature T_(max) (expressedin ° C. in table 2 below) was duly recorded by means of a thermocouple.In a few embodiments of this experimental set-up, dynamic mechanicalanalysis (hereinafter referred as DMA) was performed on the resultingpolydicyclopentadiene in order to assess its glass transitiontemperature T_(g). Results of DMA show that T_(max) is in goodaccordance (statistically significantly) with T_(g).

The following table 2 indicates the maximum temperature T_(max) obtainedwhile changing the type of additive.

TABLE 2 additive time T_(max) entry type [min.] [° C.] 1 7.3 158 2orange 6.4 176 3 yellow 4.3 189 4 glass fibres 8.2 164 5 white 6.1 172

The data presented in table 2 show that, under the above statedexperimental conditions, polydicyclopentadiene with a glass transitiontemperature T_(g) above 158° C. can reproducibly be obtained withinabout 4 to 9 minutes according to this invention, and that said highT_(g) polymer may be reinforced or coloured at will. Without wishing tobe bound by theory, it may be postulated that the T_(g) increaseobserved for entries 2-3 and 5 with respect to that of entry 1 withoutadditive may be due to the chemical constitution of the organic pigmentswhich makes them able to act as a further reactant with the chlorinatedsilane activating compound.

Example 18 Ring Opening Polymerisation of Dicyclopentadiene withActivation of a Schiff Base Ruthenium Complex

The procedure of example 17 was repeated, except that2,6-di-tert-butyl-4-sec-butylphenol was replaced with3,5-dimethylphenol, i.e. a less sterically hindered phenol, and noadditive was added in any experiment, and (only in the experimentalentry 3 of table 3) the experimental scale was increased by bringing thetotal DCPD volume to 90 ml instead of 10 ml.

The following table 3 indicates the maximum temperature T_(max) obtainedwhile changing reaction parameters such as the type of siliconactivating compound and/or its molar ratio with respect to the catalyst.

TABLE 3 activator ratio activator time T_(max) [eq.] type [min.] [° C.]entry 30 CH₃SiHCl₂ 3.6 180 1 15 SiCl₄ 4.8 185 2 30 CH₃SiHCl₂ 4.0 203 3

The data presented in table 3 show that, under the above statedexperimental conditions, polydicyclopentadiene with a glass transitiontemperature T_(g) above 180° C. can reproducibly be obtained withinabout 3 to 5 minutes according to this invention.

Example 19 Schiff Base Ligands

The eight Schiff base ligands and nitro-ligands having the formulaeshown in the following table 4 were prepared and purified according tothe method described in example 1 of WO 2005/035121.

TABLE 4 Ref. N° ligand nitro-ligand 1

2

3

4

Examples 20 to 27 Preparation of Monometallic Schiff Base SubstitutedRuthenium Complexes

Monometallic ruthenium complexes each having one Schiff base ligand ornitro-ligand from example 19, and wherein ruthenium is also coordinatedwith a chloro atom and a p-cymene group, were prepared by performing thetwo first steps of the procedure described in examples 2-8. Eachruthenium complex was characterized by means of proton NMR performedwith CDCl₃ at 25° C. as follows:

-   -   complex (example 20) obtained from the ligand 1 of example 19: δ        at 8.35 (1H), 6.85-7.20 (4H), 3.12 (3H), 5.47 (2H), 5.34 (2H),        2.92 (1H), 2.17 (3H) and 1.25 (6H) ppm;    -   complex (example 21) obtained from the ligand 2 of example 19: δ        at 8.25 (1H), 6.85-7.00 (4H), 2.54 (9H), 5.46 (2H), 5.32 (2H),        2.75 (1H), 2.24 (3H) and 1.25 (6H) ppm;    -   complex (example 22) obtained from the ligand 3 of example 19: δ        at 7.76 (1H), 7.20-7.46 (4H), 6.92-7.02 (5H), 5.49 (2H), 5.34        (2H), 2.92 (1H), 2.16 (3H), and 1.25 (6H) ppm;    -   complex (example 23) obtained from the ligand 4 of example 19: δ        at 9.25 (1H), 6.75 (2H), 2.19 (3H), 2.13 (6H), 6.80-7.60 (4H),        5.39 (2H), 5.46 (2H), 2.77 (1H), 2.16 (3H) and 1.29 (6H) ppm;    -   complex (example 24) obtained from the nitro-ligand 1 of example        19: δ at 8.00 (1H), 6.86-7.49 (3H), 3.12 (3H), 5.47 (2H), 5.34        (2H), 2.92 (1H), 2.17 (3H) and 1.25 (6H) ppm;    -   complex (example 25) obtained from the nitro-ligand 2 of example        19: δ at 8.10 (1H), 6.95-7.26 (3H), 2.54 (9H), 5.46 (2H), 5.32        (2H), 2.75 (1H), 2.24 (3H) and 1.25 (6H) ppm;    -   complex (example 26) obtained from the nitro-ligand 3 of example        19: δ at 8.06 (1H), 7.39-7.61 (3H), 6.92-6.96 (5H), 5.49 (2H),        5.34 (2H), 2.92 (1H), 2.16 (3H) and 1.25 (6H) ppm; and    -   complex (example 27) obtained from the nitro-ligand 4 of example        19: δ at 8.80 (1H), 6.75 (2H), 2.19 (3H), 2.13 (6H), 6.85-7.50        (3H), 5.39 (2H), 5.46 (2H), 2.77 (1H), 2.16 (3H) and 1.29 (6H)        ppm;

Example 28 Activation of Schiff Base Substituted Ruthenium Complexes forthe Ring-Opening Metathesis Polymerisation of Cyclooctadiene

The monometallic Schiff base substituted ruthenium complexes of examples2 to 8, the bimetallic Schiff base substituted ruthenium complexes ofexamples 9 and 10, and the monometallic Schiff base substitutedruthenium complexes of examples 20 to 27 are activated under theexperimental conditions of example 14, i.e. with:

an activating agent such as copper (I) chloride, tin tetrachloride, or achlorinated silicon compound such as HSiCl₃, HSiMe₂Cl, SiMe₂Cl₂ or SiCl₄(wherein Me stands for methyl), and

-   -   a molar ratio of said activating agent to said ruthenium complex        ranging from 70 to 1,000.        The activated Schiff base substituted ruthenium complexes are        then tested in the ring-opening metathesis polymerisation of        cyclooctadiene under the experimental conditions of example 14,        i.e. with a molar ratio of cyclooctadiene to ruthenium ranging        from 3,000 to 3,000,000 and with ion reaction times ranging from        15 to 900 minutes. Polymer conversions comparable to those        mentioned in table 1 are obtained. Polymerisation proceeds        within shorter reaction times and/or at lower reaction        temperatures as compared to the starting non-activated ruthenium        complex under the same conditions.

Example 29 Activation of Schiff Base Substituted Ruthenium Complexes forthe Ring-Opening Metathesis Polymerisation of Dicyclopentadiene

The monometallic Schiff base substituted ruthenium complexes of examples2 to 8, the bimetallic Schiff base substituted ruthenium complexes ofexamples 9 and 10, and the monometallic Schiff base substitutedruthenium complexes of examples 20 to 27 are activated in situ under theexperimental conditions of example 17, i.e. with:

-   -   CH₃Cl₂SiH as the activating agent,    -   ISONOX 132 as a reactive phenol,    -   a molar ratio of said activating agent to ruthenium of 30:1, and    -   a molar ratio of said reactive phenol to ruthenium of 60:1.

The activated Schiff base substituted ruthenium complexes formed in situare tested in the ring-opening metathesis polymerisation ofdicyclopentadiene under the experimental conditions of example 17, i.e.with a molar ratio of dicyclopentadiene to ruthenium of 30,000, andoptionally in the additional presence of additives.

Under the above stated experimental conditions, polydicyclopentadienewith a glass transition temperature T_(g) above 140° C. can reproduciblybe obtained within about 4 to 12 minutes according to this embodiment ofthe invention.

Example 30 Activation of Schiff Base Substituted Ruthenium Complexes forthe Ring-Opening Metathesis Polymerisation of Dicyclopentadiene

The monometallic Schiff base substituted ruthenium complexes of examples2 to 8, the bimetallic Schiff base substituted ruthenium complexes ofexamples 9 and 10, and the monometallic Schiff base substitutedruthenium complexes of examples 20 to 27 are activated in situ under theexperimental conditions of example 18, i.e. with:

-   -   CH₃Cl₂SiH or SiCl₄ as the activating agent,    -   3,5-dimethylphenol as a reactive phenol,    -   a molar ratio of said activating agent to ruthenium ranging from        15:1 to 30:1, and    -   a molar ratio of said reactive phenol to ruthenium of 60:1.

The activated Schiff base substituted ruthenium complexes formed in situare tested in the ring-opening metathesis polymerisation ofdicyclopentadiene under the experimental conditions of example 18, i.e.with a molar ratio of dicyclopentadiene to ruthenium of 30,000.

Under the above stated experimental conditions, polydicyclopentadienewith a glass transition temperature T_(g) above 170° C. can reproduciblybe obtained within about 3 to 10 minutes according to this embodiment ofthe invention.

Example 31 (Comparative) Ring Closing Metathesis of DiethylDiallylmalonate without Activation of a Schiff Base Ruthenium Complex

An NMR-tube was charged with a catalyst solution in CD₂Cl₂ (4.52 mM or0.002712 mmole of the Schiff base substituted ruthenium complex ofexample 11 shown as complex 70 in FIG. 5 as a catalyst). Next 200 molarequivalents (0.13 mL) of diethyl diallylmalonate was added and the NMRtube was closed. The progress of the ring closing reaction was monitoredat 30° C. by integration of ¹H signals of allylic protons of thereaction product and of the disappearing substrate. No reaction productwas obtained after 275 minutes under such conditions.

Example 32 Ring Closing Metathesis of Diethyl Diallylmalonate withActivation of a Schiff Base Ruthenium Complex

The procedure of example 31 was repeated, except that HSiCl₃ was dilutedinto diethyl diallylmalonate immediately prior to introduction into theNMR-tube, in such a way that the catalyst/substrate/HSiCl₃ ratio was1/200/50. Under such conditions, conversion of diethyl diallylmalonatewas 32.6% after 90 minutes and 63.2% after 275 minutes.

Example 33 Manufacture of a Pentacoordinated Schiff Base RutheniumComplex

The procedure of example 11, as illustrated in FIG. 5, was repeated,except that in the last step the bis(mesityl)imidazolylidene reactantwas replaced with the correspondingbis(2,6-dimethylphenyl)imidazolylidene reactant, thus forming theruthenium complex having the structure below:

This Schiff base substituted ruthenium complex was further characterisedby means of proton nuclear magnetic resonance (hereinafter referred asNMR, performed at 300 MHz with C₆D₆ at 25° C.) and carbon NMR (performedat 75 MHz with C₆D₆).

Example 34 (Comparative) Ring Closing Metathesis of DiethylDiallylmalonate without Activation of a Schiff Base Ruthenium Complex

An NMR-tube was charged with a catalyst solution in CD₂Cl₂ (4.52 mM or0.002712 mmole of the Schiff base substituted ruthenium complex ofexample 33 as a catalyst). Next 200 molar equivalents (0.13 mL) ofdiethyl diallylmalonate was added and the NMR tube was closed. Theprogress of the ring closing reaction was monitored at 22° C. byintegration of ¹H signals of allylic protons of the reaction product andof the disappearing substrate. No reaction product was obtained after180 minutes under such conditions.

Example 35 Ring Closing Metathesis of Diethyl Diallylmalonate withActivation of a Schiff Base Ruthenium Complex

The procedure of example 34 was repeated, except that HSiCl₃ was dilutedinto diethyl diallylmalonate immediately prior to introduction into theNMR-tube, in such a way that the catalyst/substrate/HSiCl₃ ratio was1/200/50. Under such conditions, conversion of diethyl diallylmalonatewas 50.7% after 180 minutes.

Example 36 Manufacture of a Pentacoordinated Schiff Base RutheniumComplex

The procedure of example 11, as illustrated in FIG. 5, was repeated,except that:

-   -   in the penultimate step, a thallium salt was used wherein R₂ is        hydrogen and R₃ is tert-butyl, and    -   in the last step the bis(mesityl)imidazolylidene reactant was        replaced with the corresponding        bis(2,6-dimethylphenyl)imidazolylidene reactant,        thus forming the ruthenium complex having the structure below:

This Schiff base substituted ruthenium complex was further characterisedby means of proton nuclear magnetic resonance (hereinafter referred asNMR, performed at 300 MHz with C₆D₆ at 25° C.) and carbon NMR (performedat 75 MHz with C₆D₆).

Example 37 (Comparative) Ring Closing Metathesis of DiethylDiallylmalonate without Activation of a Schiff Base Ruthenium Complex

An NMR-tube was charged with a catalyst solution in CD₂Cl₂ (4.52 mM or0.002712 mmole of the Schiff base substituted ruthenium complex ofexample 36 as a catalyst). Next 200 molar equivalents (0.13 mL) ofdiethyl diallylmalonate was added and the NMR tube was closed. Theprogress of the ring closing reaction was monitored at 22° C. byintegration of ¹H signals of allylic protons of the reaction product andof the disappearing substrate. Conversion was 2% after 240 minutes undersuch conditions.

Example 38 Ring Closing Metathesis of Diethyl Diallylmalonate withActivation of a Schiff Base Ruthenium Complex

The procedure of example 37 was repeated, except that HSiCl₃ was dilutedinto diethyl diallylmalonate immediately prior to introduction into theNMR-tube, in such a way that the catalyst/substrate/HSiCl₃ ratio was1/200/50. Under such conditions, conversion of diethyl diallylmalonatewas 93.3% after 14 minutes and 100% after 37 minutes.

Example 39 Manufacture of a Pentacoordinated Schiff Base RutheniumComplex

The procedure of example 11, as illustrated in FIG. 5, was repeated,except that in the penultimate step, a thallium salt was used wherein R₂is hydrogen and R₃ is tert-butyl, thus forming the ruthenium complexhaving the structure below:

This Schiff base substituted ruthenium complex was further characterisedby means of proton nuclear magnetic resonance (hereinafter referred asNMR, performed at 300 MHz with C₆D₆ at 25° C.) and carbon NMR (performedat 75 MHz with C₆D₆).

Example 40 (Comparative) Ring Closing Metathesis of DiethylDiallylmalonate without Activation of a Schiff Base Ruthenium Complex

An NMR-tube was charged with a catalyst solution in CD₂Cl₂ (4.52 mM or0.002712 mmole of the Schiff base substituted ruthenium complex ofexample 39 as a catalyst). Next 200 molar equivalents (0.13 mL) ofdiethyl diallylmalonate was added and the NMR tube was closed. Theprogress of the ring closing reaction was monitored at 22° C. byintegration of ¹H signals of allylic protons of the reaction product andof the disappearing substrate. Conversion was 2% after 240 minutes undersuch conditions.

Example 41 Ring Closing Metathesis of Diethyl Diallylmalonate withActivation of a Schiff Base Ruthenium Complex

The procedure of example 40 was repeated, except that HSiCl₃ was dilutedinto diethyl diallylmalonate immediately prior to introduction into theNMR-tube, in such a way that the catalyst/substrate/HSiCl₃ ratio was1/200/50. Under such conditions, conversion of diethyl diallylmalonatewas 92.7% after 14 minutes and 99.5% after 42 minutes.

Example 42 (Comparative) Ring Opening Polymerisation of Cyclooctadienewithout Activation of a Schiff Base Ruthenium Complex

Ring opening metathesis polymerisation of cyclooctadiene (beforehanddried over calcium hydride) was performed during 17 hours at 22° C. in0.20 mL toluene as a solvent, while using 0.002712 millimole of theSchiff base substituted ruthenium complex of example 36 as a catalyst ina molar ratio cyclooctadiene/catalyst equal to 3,000:1. Checkingconversion with NMR, no polymer was obtained after 17 hours.

Example 43 Ring Opening Polymerisation of Cyclooctadiene with Activationof a Schiff Base Ruthenium Complex

The procedure of example 42 was repeated, except that 0.0191 ml HSiCl₃was added to the reaction mixture, thus achieving acatalyst/monomer/activator ratio of 1:3,000:70. Full monomer conversionwas obtained after 1 minute.

Example 44 (Comparative) Ring Opening Polymerisation of Cyclooctadienewithout Activation of a Schiff Base Ruthenium Complex

Ring opening metathesis polymerisation of cyclooctadiene (beforehanddried over calcium hydride) was performed during 17 hours at 22° C. in0.20 mL toluene as a solvent, while using 0.002712 millimole of theSchiff base substituted ruthenium complex of example 39 as a catalyst ina molar ratio cyclooctadiene/catalyst equal to 3,000:1. Checkingconversion with NMR, no polymer was obtained after 17 hours.

Example 45 Ring Opening Polymerisation of Cyclooctadiene with Activationof a Schiff Base Ruthenium Complex

The procedure of example 44 was repeated, except that 0.0191 ml HSiCl₃was added to the reaction mixture, thus achieving acatalyst/monomer/activator ratio of 1:3,000:70. Full monomer conversionwas obtained after 1 minute.

Example 46 (Comparative) Ring Opening Polymerisation of Cyclooctadienewithout Activation of a Schiff Base Ruthenium Complex

Ring opening metathesis polymerisation of cyclooctadiene (beforehanddried over calcium hydride) was performed during 17 hours at 22° C. in0.20 mL toluene as a solvent, while using 0.002712 millimole of theSchiff base substituted ruthenium complex of example 33 as a catalyst ina molar ratio cyclooctadiene/catalyst equal to 3,000:1.

Example 47 Ring Opening Polymerisation of Cyclooctadiene with Activationof a Schiff Base Ruthenium Complex

The procedure of example 46 was repeated, except that 0.0191 ml HSiCl₃was added to the reaction mixture, thus achieving acatalyst/monomer/activator ratio of 1:3,000:70. Full monomer conversionwas obtained after 9 hours.

Example 48 (Comparative) Ring Opening Polymerisation of Cyclooctadienewithout Activation of a Schiff Base Ruthenium Complex

Ring opening metathesis polymerisation of cyclooctadiene (beforehanddried over calcium hydride) was performed during 17 hours at 22° C. in0.20 mL toluene as a solvent, while using 0.002712 millimole of theSchiff base substituted ruthenium complex of example 11 shown as complex70 in FIG. 5 as a catalyst in a molar ratio cyclooctadiene/catalystequal to 3,000:1.

Example 49 Ring Opening Polymerisation of Cyclooctadiene with Activationof a Schiff Base Ruthenium Complex

The procedure of example 48 was repeated, except that 0.0191 ml HSiCl₃was added to the reaction mixture, thus achieving acatalyst/monomer/activator ratio of 1:3,000:70. 91% monomer conversionwas obtained after 320 minutes.

Example 50 Ring Opening Polymerisation of Dicyclopentadiene withActivation of a Schiff Base Ruthenium Complex with a Silicon Compound

This example illustrates an embodiment of a ROMP process with activationof the Schiff base substituted ruthenium complex obtained in example 39(acting as the catalyst to be activated) by both HSiCl₃ and propanol.The procedure of example 17 was repeated with acatalyst/monomer/propanol/silane ratio equal to 1:30,000:90:30, andstarting from room temperature (22° C.). Reaction was allowed to proceedfor 105 seconds until temperature reached a maximum T_(max)=180° C.,after which time temperature quickly decreases. This shows that, underthese experimental conditions, polydicyclopentadiene with a glasstransition temperature T_(g) of about 180° C. can be obtained withinabout 2 minutes according to the present invention.

Example 51 Ring Opening Polymerisation of Dicyclopentadiene withActivation of a Schiff Base Ruthenium Complex with a Silicon Compound

This example illustrates an embodiment of a ROMP process with activationof the Schiff base substituted ruthenium complex of example 11 shown ascomplex 70 in FIG. 5 (acting as the catalyst to be activated) by bothHSiCl₃ and propanol. The procedure of example 17 was repeated with acatalyst/monomer/propanol/silane ratio equal to 1:30,000:90:30, startingfrom a temperature of 80° C. Reaction was allowed to proceed for 110seconds until temperature reached a maximum T_(max)=218° C., after whichtime temperature quickly decreases. This shows that, under theseexperimental conditions, polydicyclopentadiene with a glass transitiontemperature T₉ of about 218° C. can be obtained within about 2 minutesaccording to the present invention.

Example 52 Ring Opening Polymerisation of Dicyclopentadiene withActivation of a Schiff Base Ruthenium Complex with a Silicon Compound

The procedure of example 51 was repeated, except that thecatalyst/monomer/propanol/silane ratio was changed to 1:20,000:90:30,and that the experiment was started from a temperature of 60° C.Reaction was allowed to proceed for 14 minutes until temperature reacheda maximum T_(max)=201° C., after which time temperature quicklydecreases. This shows, by comparison with example 51, that in thepresence of this catalyst polymerisation is slowed down by decreasingthe monomer/catalyst ratio and decreasing the starting reactiontemperature.

Examples 53 to 55 Ring Opening Polymerisation of Dicyclopentadiene withActivation of a Schiff Base Ruthenium Complex with a Silicon Compound

The procedure of example 17 was repeated with CH₃Cl₂SiH as an activator,except that 2,6-di-tert-butyl-4-sec-butylphenol was replaced with analcohol, and that no additive was added in any experiment. Thecatalyst/monomer/alcohol/silane ratio used was 1:30,000:60:30.

The following table 5 indicates the type of alcohol used in eachexample, the maximum temperature T_(max) obtained and the time periodafter which it was achieved.

TABLE 5 alcohol time T_(max) example type [min.] [° C.] 53 1-propanol8.2 174 54 2-methyl-1-propanol 7.9 165 55 3-methyl-3buten-1-ol 9.5 182

The data presented in table 5 show that it is possible to modulate theglass transition temperature T_(g) of the polymer obtained whilechanging the type of further reactant used together with the silaneactivator but without significantly changing the time needed forobtaining full polymerisation.

Examples 56 and 57 Ring Opening Polymerisation of Dicyclopentadiene withActivation of a Schiff Base Ruthenium Complex with a Titanium Compound

The procedure of example 17 was repeated except that TiCl₄ was used asan activator, 2,6-di-tert-butyl-4-sec-butylphenol was replaced with analcohol or another phenol, and no additive was added in any experiment.The catalyst/monomer/alcohol(phenol)/titanium molar ratio used was1:30,000:90:22.5.

The following table 6 indicates the type of co-reactant used in eachexample, the maximum temperature T_(max) obtained and the time periodafter which it was achieved.

TABLE 6 Co-reactant time T_(max) example type [min.] [° C.] 561-propanol 2.0 201 57 3,5-dimethylphenol 1.1 202

The data presented in table 6 show that it is possible to keep theadvantage of a high glass transition temperature T_(g) of the polymerobtained while changing the type of activator and while significantlydecreasing the time period required for obtaining full polymerisation.

Examples 58 to 60 Ring Opening Polymerisation of Dicyclopentadiene withActivation of a Schiff Base Ruthenium Complex with an Aluminium Compound

The procedure of example 17 was repeated except that AlCl₃ was used asan activator, 2,6-di-tert-butyl-4-sec-butylphenol (ISONOX 132) may bereplaced with n-propanol or 3,5-dimethylphenol, and no additive wasadded in any experiment. The catalyst/monomer/alcohol(phenol)/aluminiummolar ratio used was 1:30,000:90:30.

The following table 7 indicates the type of co-reactant used in eachexample, the maximum temperature T_(max) obtained and the time periodafter which it was achieved.

TABLE 7 alcohol time T_(max) example type [min.] [° C.] 58 1-propanol3.3 163 59 3,5-dimethylphenol 1.2 170 60 ISONOX 132 1.0 172

The data presented in table 7 show that it is possible to modulate theglass transition temperature T_(g) of the polymer obtained whilechanging the type of activator and while significantly decreasing thetime period required for obtaining full polymerisation.

Example 61 Ring Opening Polymerisation of Dicyclopentadiene withActivation of a Schiff Base Ruthenium Complex with a Tin Compound

The procedure of example 17 was repeated except that SnCl₄ was used asan activator, 2,6-di-tert-butyl-4-sec-butylphenol was replaced withn-propanol, and no additive was added in any experiment. Thecatalyst/monomer/propanol/tin molar ratio used was 1:30,000:90:22.5.Reaction was allowed to proceed for 171 seconds until temperaturereached a maximum T_(max)=178° C., after which time temperature quicklydecreases. This shows that, under these experimental conditions,polydicyclopentadiene with a glass transition temperature T_(g) of about178° C. can be obtained within less than 3 minutes in the presence of atin-based activating compound.

Examples 62 to 64 Ring Opening Polymerisation of Dicyclopentadiene withActivation of a Schiff Base Ruthenium Complex with Silicon Tetrachloride

The procedure of example 17 was repeated except that SiCl₄ was used asan activator, 2,6-di-tert-butyl-4-sec-butylphenol (ISONOX 132) may bereplaced with n-propanol or 3,5-dimethylphenol, and no additive wasadded in any experiment. The catalyst/monomer/alcohol(phenol)/siliconmolar ratio used was 1:30,000:90:22.5.

The following table 8 indicates the type of co-reactant used in eachexample, the maximum temperature T_(max) obtained and the time periodafter which it was achieved.

TABLE 8 co-reactant time T_(max) example type [min.] [° C.] 621-propanol 4.0 184 63 3,5-dimethylphenol 6.5 181 64 ISONOX 132 6.5 184

Examples 65 and 66 Ring Opening Polymerisation of Dicyclopentadiene withActivation of a Schiff Base Ruthenium Complex with a Silicon Compound

The procedure of example 17 was repeated except that HSiCl₃ was used asan activator, 2,6-di-tert-butyl-4-sec-butylphenol (ISONOX 132) wasreplaced with n-propanol or 3,5-dimethylphenol, and no additive wasadded in any experiment. The catalyst/monomer/alcohol(phenol)/siliconmolar ratio used was 1:30,000:90:30.

The following table 9 indicates the type of co-reactant used in eachexample, the maximum temperature T_(max) obtained and the time periodafter which it was achieved.

TABLE 9 co-reactant time T_(max) example type [min.] [° C.] 651-propanol 5.0 185 66 3,5-dimethylphenol 2.0 200

Example 67 Ring Opening Polymerisation of Dicyclopentadiene withActivation of a Schiff Base Ruthenium Complex with a Phosphorus Compound

The procedure of example 17 was repeated except that PBr₃ was used as anactivator, 2,6-di-tert-butyl-4-sec-butylphenol was replaced with3,5-dimethylphenol, and no additive was added in this experiment. Thecatalyst/monomer/phenol/phosphorous molar ratio used was 1:30,000:90:30.Reaction was allowed to proceed for 11.4 minutes until temperaturereached a maximum T_(max)=156° C., after which time temperature quicklydecreases. This shows that, under these experimental conditions,polydicyclopentadiene with a glass transition temperature T_(g) of about156° C. can be obtained in the presence of a phosphorous-basedactivating compound.

Examples 68 and 69 Ring Opening Polymerisation of Dicyclopentadiene withActivation of a Schiff Base Ruthenium Complex with a Silicon Compound

The procedure of example 17 was repeated except that H(CH₃)SiCl₂ wasused as an activator, 2,6-di-tert-butyl-4-sec-butylphenol (ISONOX 132)was replaced with a monocarboxylic acid, and no additive was added inany experiment. The catalyst/monomer/acid/silicon molar ratio used was1:30,000:60:30.

The following table 10 indicates the type of co-reactant used in eachexample, the maximum temperature T_(max) obtained and the time periodafter which it was achieved.

TABLE 10 co-reactant time T_(max) example type [min.] [° C.] 68 Aceticacid 7.5 174 69 Benzoic acid 12.7 177

All publications and patent applications mentioned in this specificationare herein incorporated by reference to the same extent as if eachindependent publication or patent application was specifically andindividually indicated to be incorporated by reference.

What is claimed is:
 1. A method of modifying a multi-coordinated metalcomplex, a salt, a solvate or an enantiomer thereof, saidmulti-coordinated metal complex comprising (i) at least one multidentateSchiff base ligand comprising an imino group and being coordinated tothe metal, in addition to the nitrogen atom of said imino group, throughat least one further heteroatom selected from the group consisting ofoxygen, sulfur and selenium, and (ii) one or more other ligands, whereinsaid method comprises bringing said multi-coordinated metal complex intocontact with an activating compound under conditions such that at leastpartial cleavage of a bond between the metal and said at least onemultidentate Schiff base ligand (i) occurs, and wherein said activatingcompound is either a metal or silicon compound selected from the groupconsisting of: copper (I) halides, zinc compounds represented by theformula Zn(R₅)₂, wherein R₅ is halogen, C₁₋₇ alkyl or aryl, tincompounds represented by the formula SnR₉R₁₀R₁₁R₁₂ wherein each of R₉,R₁₀, R₁₁ and R₁₂ is independently selected from the group consisting ofhalogen, C₁₋₂₀ alkyl, C₃₋₁₀ cycloalkyl, aryl, benzyl and C₂₋₇ alkenyl,and silicon compounds represented by the formula SiR₁₃R₁₄R₁₅R₁₆ whereineach of R₁₃, R₁₄, R₁₅ and R₁₆ is independently selected from the groupconsisting of hydrogen, halogen, C₁₋₂₀ alkyl, halo C₁₋₇ alkyl, aryl,heteroaryl and vinyl, or a compound comprising at least one halogen atomdirectly bonded to at least one atom having an atomic mass from 27 to124 and being selected from the group consisting of groups IB, IIB,IIIA, IVB, IVA and VA of the Periodic Table of elements.
 2. A methodaccording to claim 1, wherein said conditions include a molar ratiobetween said activating compound and the metal of said multi-coordinatedmetal complex being from about 5:1 to about 2,000:1.
 3. A methodaccording to claim 1, wherein said conditions include a contact timefrom about 5 seconds to about 100 hours.
 4. A method according to claim1 wherein said conditions include a contact temperature from about −50°C. to about 80° C.
 5. A method according to claim 1, wherein at leastone of said other ligands (ii) is a constraint steric hindrance ligandhaving a pKa of at least
 15. 6. A method according to claim 1, whereinthe number of carbon atoms in said at least one multidentate Schiff baseligand (i), between the nitrogen atom of said imino group and saidcoordinating heteroatom of said at least one multidentate Schiff baseligand (i), is from 2 to
 4. 7. A method according to claim 1 wherein atleast one of said other ligands (ii) is a carbene ligand selected fromthe group consisting of N-heterocyclic carbenes, alkylidene ligands,vinylidene ligands, indenylidene ligands, heteroatom-containingalkylidene ligands and allenylidene ligands.
 8. A method according toclaim 1 wherein at least one of said other ligands (ii) is an anionicligand.
 9. A method according to claim 1 wherein at least one of saidother ligands (ii) is a non-anionic ligand.
 10. A method according toclaim 1 wherein said at least one atom having an atomic mass from 27 to124 is selected from the group consisting of copper, zinc, tin, silicon,titanium, aluminium and phosphorous.
 11. A method according to claim 1,wherein said activating compound includes at least one halogen atom andwherein bringing said multi-coordinated metal complex into contact withsaid activating compound is effected in the presence of at least onefurther reactant being an organic acid or having the structural formulaRYH, wherein Y is selected from the group consisting of oxygen, sulfurand selenium, and R is selected from the group consisting of hydrogen,aryl, arylalkyl, heteocyclic, heterocyclic-substituted alkyl, C₂₋₇alkenyl and C₁₋₇ alkyl.
 12. A method according to claim 1, wherein saidactivating compound includes at least one halogen atom and whereinbringing said multi-coordinated metal complex into contact with saidactivating compound is effected in the presence of at least oneoptionally substituted phenol or C₁₋₇ alkyl alcohol or C₂₋₇ alkenylalcohol or a monocarboxylic or polycarboxylic acid.
 13. A methodaccording to claim 1, wherein bringing said multi-coordinated metalcomplex into contact with said activating compound is effected in thepresence of at least one optionally substituted phenol, and wherein saidactivating compound is selected from the group consisting ofmethyldichlorosilane, trichlorosilane, alkyltrichlorosilanes,dialkyl-dichlorosilanes, trialkylchlorosilanes and silicontetrachloride.
 14. A method according to claim 1, wherein saidactivating compound includes at least one halogen atom and whereinbringing said multi-coordinated metal complex into contact with saidactivating compound is effected in the presence of at least one furtherreactant being an organic acid or having the structural formula RYH,wherein Y is selected from the group consisting of oxygen, sulfur andselenium, and R is selected from the group consisting of hydrogen, aryland C₁₋₄ alkyl, and wherein the molar ratio of said at least one furtherreactant with respect to said activating compound is such that eachlabile hydrogen atom of said further reactant is able to react with eachhalogen atom of said activating compound.